ORCID Profile
0000-0001-5302-360X
Current Organisation
Deakin University - Geelong Campus at Waurn Ponds
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Additive manufacturing | Mechanical engineering | Manufacturing robotics | Numerical modelling and mechanical characterisation |
ANZSRC Socio-Economic Objective (SEO)
Related Links
Publications
Influence of Infill Patterns Generated by CAD and FDM 3D Printer on Surface Roughness and Tensile Strength Properties
Publisher: MDPI AG
Date: 07-08-2021
DOI: 10.3390/APP11167272
Abstract: Fused deposition modeling (FDM) is a capable technology based on a wide range of parameters. The goal of this study is to make a comparison between infill pattern and infill density generated by computer-aided design (CAD) and FDM. Grid, triangle, zigzag, and concentric patterns with various densities following the same structure of the FDM machine were designed by CAD software (CATIA V5®). Polylactic acid (PLA) material was assigned for both procedures. Surface roughness (SR) and tensile strength analysis were conducted to examine their effects on dog-bone s les. Also, a finite element analysis (FEA) was done on CAD specimens to find out the differences between printing and simulation processes. Results illustrated that CAD specimens had a better surface texture compared to the FDM machine while tensile tests showed patterns generated by FDM were stronger in terms of strength and stiffness. In this study, s les with concentric patterns had the lowest average SR (Ra) while zigzag was the worst with the value of 6.27 µm. Also, the highest strength was obtained for concentric and grid s les in both CAD and FDM procedures. These techniques can be useful in producing highly complex sandwich structures, bone scaffolds, and various combined patterns to achieve an optimal condition.
Constitutive Modeling of multi-stimuli-responsive shape memory polymers with multi-functional capabilities
Publisher: Elsevier BV
Date: 02-2021
An electroactive polymer composite with reinforced bending strength, based on tubular micro carbonized-cellulose
Publisher: Elsevier BV
Date: 02-2018
Design, evaluation, and optimization of 3D printed truss scaffolds for bone tissue engineering
Publisher: Elsevier BV
Date: 08-2021
Energy Absorption and Mechanical Performance of Functionally Graded Soft–Hard Lattice Structures
Publisher: MDPI AG
Date: 11-03-2021
DOI: 10.3390/MA14061366
Abstract: Today, the rational combination of materials and design has enabled the development of bio-inspired lattice structures with unprecedented properties to mimic biological features. The present study aims to investigate the mechanical performance and energy absorption capacity of such sophisticated hybrid soft–hard structures with gradient lattices. The structures are designed based on the ersity of materials and graded size of the unit cells. By changing the unit cell size and arrangement, five different graded lattice structures with various relative densities made of soft and hard materials are numerically investigated. The simulations are implemented using ANSYS finite element modeling (FEM) (2020 R1, 2020, ANSYS Inc., Canonsburg, PA, USA) considering elastic-plastic and the hardening behavior of the materials and geometrical non-linearity. The numerical results are validated against experimental data on three-dimensional (3D)-printed lattices revealing the high accuracy of the FEM. Then, by combination of the dissimilar soft and hard polymeric materials in a homogenous hexagonal lattice structure, two dual-material mechanical lattice statures are designed, and their mechanical performance and energy absorption are studied. The results reveal that not only gradual changes in the unit cell size provide more energy absorption and improve mechanical performance, but also the rational combination of soft and hard materials make the lattice structure with the maximum energy absorption and stiffness, in comparison to those structures with a single material, interesting for multi-functional applications.
Nonlinear Finite Element Modelling of Thermo-Visco-Plastic Styrene and Polyurethane Shape Memory Polymer Foams
Publisher: MDPI AG
Date: 28-02-2021
DOI: 10.3390/ACT10030046
Abstract: This paper presents nonlinear finite element (FE) models to predict time- and temperature-dependent responses of shape memory polymer (SMP) foams in the large deformation regime. For the first time, an A SMP foam constitutive model is implemented in the ABAQUS FE package with the aid of a VUMAT subroutine to predict thermo-visco-plastic behaviors. A phenomenological constitutive model is reformulated adopting a multiplicative decomposition of the deformation gradient into thermal and mechanical parts considering visco-plastic SMP matrix and glass microsphere inclusions. The stress split scheme is considered by a Maxwell element in parallel with a hyper-elastic rubbery spring. The Eyring dashpot is used for modelling the isotropic resistance to the local molecular rearrangement such as chain rotation. A viscous flow rule is adopted to prescribe shear viscosity and stress. An evolution rule is also considered for the athermal shear strengths to simulate macroscopic post-yield strain-softening behavior. In order to validate the accuracy of the model as well as the solution procedure, the numerical results are compared to experimental responses of Styrene and Polyurethane SMP foams at different temperatures and under different strain rates. The results show that the introduced FE modelling procedure is capable of capturing the major phenomena observed in experiments such as elastic and elastic-plastic behaviors, softening plateau regime, and densification.
Recent progress of 4D printing in cancer therapeutics studies
Publisher: Elsevier BV
Date: 06-2023
A novel spectral relaxation approach for nanofluid flow past a stretching surface in presence of magnetic field and nonlinear radiation
Publisher: Elsevier BV
Date: 2022
Patient-specific 3D-printed Splint for Mallet Finger Injury
Publisher: AccScience Publishing
Date: 27-03-2020
Abstract: Despite the frequency of mallet finger injuries, treatment options can often be costly, time-consuming, and ill-fitted. Three-dimensional (3D) printing allows for the production of highly customized and inexpensive splints, which suggests potential efficacy in the prescription of casts for musculoskeletal injuries. This study explores how the use of engineering concepts such as 3D printing and topology optimization (TO) can improve outcomes for patients. 3D printing enables the direct fabrication of the patient-specific complex shapes while utilizing finite element analysis and TO in the design of the splint allowed for the most efficient distribution of material to achieve mechanical requirements while reducing the amount of material used. The reduction in used material leads to significant improvements in weight reduction and heat dissipation, which would improve breathability and less sweating for the patient, greatly increasing comfort for the duration of their recovery.
Stimuli-Responsive Polymer Systems—Recent Manufacturing Techniques and Applications
Publisher: MDPI
Date: 17-09-2019
4D printing of soft orthoses for tremor suppression
Publisher: Springer Science and Business Media LLC
Date: 07-06-2022
DOI: 10.1007/S42242-022-00199-Y
Abstract: Tremor is an involuntary and oscillatory movement disorder that makes daily activities difficult for affected patients. Hand tremor-suppression orthoses are noninvasive, wearable devices designed to mitigate tremors. Various studies have shown that these devices are effective, economical, and safe however, they have drawbacks such as large weight, awkward shape, and rigid parts. This study investigates different types of tremor-suppression orthoses and discusses their efficiency, mechanism, benefits, and disadvantages. First, various orthoses (with passive, semi-active, and active mechanisms) are described in detail. Next, we look at how additive manufacturing (AM) has progressed recently in making sensors and actuators for application in tremor orthoses. Then, the materials used in AM are further analyzed. It is found that traditional manufacturing problems can be solved with the help of AM techniques, like making orthoses that are affordable, lighter, and more customizable. Another concept being discussed is using smart materials and AM methods, such as four-dimensional (4D) printing, to make orthoses that are more comfortable and efficient. Graphic abstract
Effects of Topology Optimization in Multimaterial 3D Bioprinting of Soft Actuators
Publisher: AccScience Publishing
Date: 10-04-2020
Abstract: Recently, there has been a proliferation of soft robots and actuators that exhibit improved capabilities and adaptability through three-dimensional (3D) bioprinting. Flexibility and shape recovery attributes of stimuli-responsive polymers as the main components in the production of these dynamic structures enable soft manipulations in fragile environments, with potential applications in biomedical and food sectors. Topology optimization (TO), when used in conjunction with 3D bioprinting with optimal design features, offers new capabilities for efficient performance in compliant mechanisms. In this paper, multimaterial TO analysis is used to improve and control the bending performance of a bioprinted soft actuator with electrolytic stimulation. The multimaterial actuator performance is evaluated by the litude and rate of bending motion and compared with the single material printed actuator. The results demonstrated the efficacy of multimaterial 3D bioprinting optimization for the rate of actuation and bending.
Intelligent active force control of a 3-RRR parallel manipulator incorporating fuzzy resolved acceleration control
Publisher: Elsevier BV
Date: 06-2012
Soft Pneumatic Actuators: A Review of Design, Fabrication, Modeling, Sensing, Control and Applications
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2022
Reversible energy absorption of elasto-plastic auxetic, hexagonal, and AuxHex structures fabricated by FDM 4D printing
Publisher: IOP Publishing
Date: 19-04-2022
Abstract: The present study aims at introducing reconfigurable mechanical metamaterials by utilising four-dimensional (4D) printing process for recoverable energy dissipation and absorption applications with shape memory effects. The architected mechanical metamaterials are designed as a repeating arrangement of re-entrant auxetic, hexagonal, and AuxHex unit-cells and manufactured using 3D printing fused deposition modelling process. The AuxHex cellular structure is composed of auxetic re-entrant and hexagonal components. Architected cellular metamaterials are developed based on a comprehension of the elasto-plastic features of shape memory polylactic acid materials and cold programming deduced from theory and experiments. Computational models based on ABAQUS/Standard are used to simulate the mechanical properties of the 4D-printed mechanical metamaterials under quasi-static uniaxial compression loading, and the results are validated by experimental data. Research trials show that metamaterial with re-entrant auxetic unit-cells has better energy absorption capability compared to the other structures studied in this paper, mainly because of the unique deformation mechanisms of unit-cells. It is shown that mechanical metamaterials with elasto-plastic behaviors exhibit mechanical hysteresis and energy dissipation when undergoing a loading-unloading cycle. It is experimentally revealed that the residual plastic strain and dissipation processes induced by cold programming are completely reversible through simple heating. The results and concepts presented in this work can potentially be useful towards 4D printing reconfigurable cellular structures for reversible energy absorption and dissipation engineering applications.
Multimaterial 4D printing with a tunable bending model
Publisher: IOP Publishing
Date: 21-04-2023
Abstract: Shape-memory polymer (SMP)-based functional structures may now be produced more efficiently via four-dimensional (4D) printing, benefiting from the recent advances in multi-material three-dimensional printing technologies. Composite material design using 4D printing has opened new possibilities for customizing the shape memory property of smart polymers. This work studies a design strategy to harness desirable morphing by 4D printing multimaterial composites with a focus on the detailed finite element (FE) procedure, experimental results, and soft robotic application. Composites with bilayer laminates consisting of a SMP and a flexible elastomer are constructed with variable thickness ratios to control the self-bending of the composite. FE simulations are used to understand the underlying processes of composite materials and to generate accurate predictions for the experimental results, which reduces cost and development time. The application of 4D printing and multi-material composite programming is demonstrated with a soft robotic gripper for manipulating fragile objects.
Structural performance of 3D-printed composites under various loads and environmental conditions
Publisher: Elsevier BV
Date: 11-2020
4D printing parameters optimisation for bi-stable soft robotic gripper design
Publisher: Springer Science and Business Media LLC
Date: 29-03-2023
DOI: 10.1007/S40430-023-04171-4
Abstract: Four-dimensional (4D) printing is an emerging additive manufacturing (AM) technology that adds a time-dependent reconfiguration dimension to three-dimensional (3D) printed products. It enables the creation of on-demand, dynamically controllable shapes, or properties in response to external stimuli such as temperature, magnetic field, and light. Thermally responsive structures are among the most popular types of currently available 4D-printed structures due to their convenience. However, applications like soft robots are hindered by the temperature-sensitive structures' stagnating actuation. This research was driven by a requirement for a rapid and effective design and optimisation strategy for 4D-printed bi-stable thermally responsive structures for use in soft robotics. In this study, the response surface method (RSM) optimization with the aid of numerical solutions was used to investigate effective parameters in the design of a bi-stable, 4D-printed soft robotic gripper. This approach is proposed to accelerate the actuation of thermally responsive shape-morphing structures that can be controlled by the in situ strains and post-manufacturing heat stimuli as variable parameters. By using RSM solution the in idual effects as well as the coupling effects of variable parameters on the output responses, including the maximum strain energy and the average distance between the cl s of the structure, are evaluated. The obtained results can be employed to develop the designation and improve the acceleration of soft robotic grippers such as fast buckling and bending, which is desirable for soft robotic applications. Graphical abstract
3D Printing of a Photo-thermal Self-folding Actuator
Publisher: Knowledge E
Date: 09-02-2017
Abstract: The demand for rapid and accurate fabrication of light-weight, biocompatible, and soft actuators in soft robotics has perused researchers to design and fabricate such products by rapid manufacturing techniques. The self-folding origami structure is a type of soft actuator that has applications in micro electro mechanical systems, soft electronics, and biomedical devices. 3-dimentional (3D) printing is a current manufacturing process that can be used for fabrication of involute soft self-folding products by means of shape memory polymer materials. This paper presents, for the first time, a method for developing a photo thermal self-folding soft actuator using a 3D bioplotter. Easily accessible and inexpensive pre-strained polystyrene is opted for the backbone of actuator. The polystyrene film (PS) is then structured in a hand shape gripper. Chitosan hydrogel and carbon black ink were combined for printing active hinges on the hand gripper. Various active hinges with different widths and thicknesses were printed on the hand gripper using the 3D bioplotter. An infra-red (IR) heating l was placed at a reasonable distance to emit IR light uniformly on the hand gripper. The temperature distribution on the hand gripper was observed using a thermographic camera and the bending angles of the s les were recorded by a video camera. It was observed that the bending angles of the hand fingers depend on factors such as the intensity of the heat flux generated by the IR light intensity, distance, onset temperature, geometry of the fingers such as width and thickness, and area of the hinges.
Analysis of nano droplet dynamics with various sphericities using efficient computational techniques
Publisher: Springer Science and Business Media LLC
Date: 10-2017
Evolution of 3D printed soft actuators
Publisher: Elsevier BV
Date: 10-2016
Functional Polymers in Sensors and Actuators: Fabrication and Analysis
Publisher: MDPI AG
Date: 15-07-2020
Abstract: Recent advances in fabrication techniques have enabled the production of different types of polymer sensors and actuators that can be utilized in a wide range of applications, such as soft robotics, biomedical, smart textiles and energy harvesting [...]
3D printed hydrogel soft actuators
Publisher: IEEE
Date: 11-2016
Fracture and load-carrying capacity of 3D-printed cracked components
Publisher: Elsevier BV
Date: 05-2020
Functionally graded additive manufacturing for orthopedic applications
Publisher: Elsevier BV
Date: 09-2022
4D Printing for Vascular Tissue Engineering: Progress and Challenges
Publisher: Wiley
Date: 07-05-2023
Abstract: The hierarchical network of blood vessels comprises the larger vessels (veins and arteries), the smaller ones (venules and arterioles), and the thinnest capillaries. The proper functioning of most tissues in the body relies on vascularization, which is meant for the diffusion of gases, nutrients, and harmful waste. However, it is known that cell survival is compromised as the diffusion of oxygen is limited beyond 100–200 µm and damage can occur at any level of the complex system of the vascular network, as is the case in cardiovascular, musculoskeletal, and neurovascular diseases that recur and progress with age. These may prove fatal, hence the need for vascular tissue engineering (VTE) arises. VTE mainly focuses on the fabrication of vascular constructs using natural, synthetic material, or a combination of both using various techniques. The construct is expected to integrate and anastomose with the host vasculature. 4D bioprinting is an emerging field that allows the fabrication of hollow tubes employing different materials that respond to different stimuli. This review is a comprehensive summary of the major techniques employed in VTE and the recent technique of 4D bioprinting foreseen to revolutionize the field.
Dynamic nanocellulose hydrogels: Recent advancements and future outlook
Publisher: Elsevier BV
Date: 10-2021
Finite Element Methods in Smart Materials and Polymers
Publisher: MDPI
Date: 03-09-2020
Shape-Adaptive Metastructures with Variable Bandgap Regions by 4D Printing
Publisher: MDPI AG
Date: 03-2020
Abstract: This article shows how four-dimensional (4D) printing technology can engineer adaptive metastructures that exploit resonating self-bending elements to filter vibrational and acoustic noises and change filtering ranges. Fused deposition modeling (FDM) is implemented to fabricate temperature-responsive shape-memory polymer (SMP) elements with self-bending features. Experiments are conducted to reveal how the speed of the 4D printer head can affect functionally graded prestrain regime, shape recovery and self-bending characteristics of the active elements. A 3D constitutive model, along with an in-house finite element (FE) method, is developed to replicate the shape recovery and self-bending of SMP beams 4D-printed at different speeds. Furthermore, a simple approach of prestrain modeling is introduced into the commercial FE software package to simulate material tailoring and self-bending mechanism. The accuracy of the straightforward FE approach is validated against experimental observations and computational results from the in-house FE MATLAB-based code. Two periodic architected temperature-sensitive metastructures with adaptive dynamical characteristics are proposed to use bandgap engineering to forbid specific frequencies from propagating through the material. The developed computational tool is finally implemented to numerically examine how bandgap size and frequency range can be controlled and broadened. It is found out that the size and frequency range of the bandgaps are linked to changes in the geometry of self-bending elements printed at different speeds. This research is likely to advance the state-of-the-art 4D printing and unlock potentials in the design of functional metastructures for a broad range of applications in acoustic and structural engineering, including sound wave filters and waveguides.
Additive Manufacturing of Composite Foam Metamaterial Springs for Vibration Isolation
Publisher: Wiley
Date: 24-08-2023
Abstract: This research introduces a novel approach for reducing the vibrations experienced by passengers in vehicles using metamaterials embedded in polyurethane foam to improve the existing vibration isolation capacity of car seats. An exploration of quasizero and negative stiffness metamaterials is conducted to develop metamaterial springs that exhibit a region of high‐static and low‐dynamic stiffness to achieve vibration isolation. Metamaterials are developed using low‐cost open‐source additive manufacturing methods and thermoplastic polyurethane filament. This investigation follows a process of determining the geometric, material, and systemic design requirements, to identify the quasizero and negative‐stiffness force–displacement regions. Small‐scale models of a car seat are developed by embedding the designed metamaterials into different grades of polyurethane foam and completing static and dynamic testing. The results demonstrate practical applications for implementing metamaterial springs into polyurethane foam to enhance vibration isolation under dynamic loading. The developed material library and the key geometric variables in the metamaterial design allow for application‐specific solutions where the selection of the appropriate metamaterial and foam combination can be tailored to suit the system requirements.
Reversible energy absorbing meta-sandwiches by FDM 4D printing
Publisher: Elsevier BV
Date: 05-2020
Topology-Optimized 4D Printing of a Soft Actuator
Publisher: Springer Science and Business Media LLC
Date: 10-09-2019
Performance Analysis of the Computed Torque Based Active Force Control for a Planar Parallel Manipulator
Publisher: Trans Tech Publications, Ltd.
Date: 24-10-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMM.110-116.4932
Abstract: This paper presents a novel approach to control a 3-RRR (revolute-revolute-revolute) planar parallel manipulator applying an active force control (AFC) strategy. A PID-based computed torque controller (CTC) was first designed and developed to demonstrate the basic and stable response of the manipulator in order to follow a prescribed trajectory. Then, the AFC part was incorporated into the control scheme in series with the CTC (AFC-CTC) in a cascade form. Performance of the system was demonstrated by the computer simulation results. By using the AFC method, the design of trajectory tracking controller can be conducted based on a precise model of the system. The overall tracking performance was improved with using AFC scheme in presence of known or unknown disturbances. Results clearly illustrate the robustness and effectiveness of the proposed AFC-based scheme as a robust disturbance rejecter compared to the conventional CT controller.
AI-Based Soft Module for Safe Human–Robot Interaction towards 4D Printing
Publisher: MDPI AG
Date: 13-08-2022
Abstract: Soft robotic modules have potential use for therapeutic and educational purposes. To do so, they need to be safe, soft, smart, and customizable to serve in iduals’ different preferences and personalities. A safe modular robotic product made of soft materials, particularly silicon, programmed by artificial intelligence algorithms and developed via additive manufacturing would be promising. This study focuses on the safe tactile interaction between humans and robots by means of soft material characteristics for translating physical communication to auditory. The embedded vibratory sensors used to stimulate touch senses transmitted through soft materials are presented. The soft module was developed and verified successfully to react to three different patterns of human–robot contact, particularly users’ touches, and then communicate the type of contact with sound. The study develops and verifies a model that can classify different tactile gestures via machine learning algorithms for safe human–robot physical interaction. The system accurately recognizes the gestures and shapes of three-dimensional (3D) printed soft modules. The gestures used for the experiment are the three most common, including slapping, squeezing, and tickling. The model builds on the concept of how safe human–robot physical interactions could help with cognitive and behavioral communication. In this context, the ability to measure, classify, and reflect the behavior of soft materials in robotic modules represents a prerequisite for endowing robotic materials in additive manufacturing for safe interaction with humans.
Fracture Resistance Analysis of 3D-Printed Polymers
Publisher: MDPI AG
Date: 02-02-2020
Abstract: Three-dimensional (3D)-printed parts are an essential subcategory of additive manufacturing with the recent proliferation of research in this area. However, 3D-printed parts fabricated by different techniques differ in terms of microstructure and material properties. Catastrophic failures often occur due to unstable crack propagations and therefore a study of fracture behavior of 3D-printed components is a vital component of engineering design. In this paper, experimental tests and numerical studies of fracture modes are presented. A series of experiments were performed on 3D-printed nylon s les made by fused deposition modeling (FDM) and multi-jet fusion (MJF) to determine the load-carrying capacity of U-notched plates fabricated by two different 3D printing techniques. The equivalent material concept (EMC) was used in conjunction with the J-integral failure criterion to investigate the failure of the notched s les. Numerical simulations indicated that when EMC was combined with the J-integral criterion the experimental results could be predicted successfully for the 3D-printed polymer s les.
Sustainable Robots 4D Printing
Publisher: Wiley
Date: 09-2023
Rigid elements dynamics modeling of a 3D printed soft actuator
Publisher: IOP Publishing
Date: 20-12-2018
Unwanted noise and vibration control using finite element analysis and artificial intelligence
Publisher: Elsevier BV
Date: 05-2014
Practical multi-objective controller for preventing noise and vibration in an automobile wiper system
Publisher: Elsevier BV
Date: 02-2013
Stimuli-Responsive Polymer Systems—Recent Manufacturing Techniques and Applications
Publisher: MDPI AG
Date: 26-07-2019
DOI: 10.3390/MA12152380
Abstract: Stimuli-responsive polymer systems can be defined as functional materials that show physical or chemical property changes in response to external stimuli, such as temperature, radiation, chemical agents, pH, mechanical stress, and electric and magnetic fields [...]
Electrothermal Modeling and Analysis of Polypyrrole-Coated Wearable E-Textiles
Publisher: MDPI AG
Date: 24-01-2021
DOI: 10.3390/MA14030550
Abstract: The inhomogeneity of the resistance of conducting polypyrrole-coated nylon–Lycra and polyester (PET) fabrics and its effects on surface temperature were investigated through a systematic experimental and numerical work including the optimization of coating conditions to determine the lowest resistivity conductive fabrics and establish a correlation between the fabrication conditions and the efficiency and uniformity of Joule heating in conductive textiles. For this purpose, the effects of plasma pre-treatment and molar concentration analysis of the dopant anthraquinone sulfonic acid (AQSA), oxidant ferric chloride, and monomer pyrrole was carried out to establish the conditions to determine the s le with the lowest electrical resistance for generating heat and model the experiments using the finite element modeling (FEM). Both PET and nylon-Lycra underwent atmospheric plasma treatment to functionalize the fabric surface to improve the binding of the polymer and obtain coatings with reduced resistance. Both fabrics were compared in terms of average electrical resistance for both plasma treated and untreated s les. The plasma treatment induced deep black coatings with lower resistance. Then, heat-generating experiments were conducted on the polypyrrole (PPy) coated fabrics with the lowest resistance using a variable power supply to study the distribution and maximum value of the temperature. The joule heating model was developed to predict the heating of the conductive fabrics via finite element analysis. The model was based on the measured electrical resistance at different zones of the coated fabrics. It was shown that, when the fabric was backed with neoprene insulation, it would heat up quicker and more evenly. The average electrical resistance of the PPy-PET s le used was 190 Ω, and a maximum temperature reading of 43 °C was recorded. The model results exhibited good agreement with thermal camera data.
A nonparametric approach using artificial intelligence in vibration and noise reduction of flexible systems
Publisher: SAGE Publications
Date: 28-10-2013
Abstract: The main aim of this paper is to broaden the application’s area of artificial intelligence including fuzzy logic and multiobjective evolutionary algorithm into real-time control area. Wiper system is a high order, nonlinear model with single-input and multi-outputs so that rise time, maximum overshoot, and end-point vibration of wiper blade are observed in conflict as the faster response leads to the larger level of undesired noise and vibration. The first part of this paper centers acquiring experimental data from a passenger automobile wiper system during its operation and using a reliable nonlinear system identification, namely, nonlinear autoregressive exogenous Elman neural network. Knowing that in a practical environment, where the loading conditions of the flexible wiper blade may be varied due to rain, snow, or wind lift in high-speed driving, causing changes in the characteristics of the system, the system performance with a fixed conventional controller scheme will not be satisfactory. The main contribution of this work is presented in second part where a novel multiobjective, bilevel adaptive-fuzzy controller is proposed for an automobile wiper system. The system’s parameters are tuned simultaneously by a multiobjective genetic algorithm based on fitness sharing whereby an automobile wiper blade is moved within its sweep workspace in the least amount of time with minimum noise and vibration.
Focus on 4D materials design and additive manufacturing
Publisher: IOP Publishing
Date: 26-09-2023
Analytical thermal study on nonlinear fundamental heat transfer cases using a novel computational technique
Publisher: Elsevier BV
Date: 04-2016
Polyelectrolyte Soft Actuators: 3D Printed Chitosan and Cast Gelatin
Publisher: Mary Ann Liebert Inc
Date: 06-2018
Finite Element Methods in Smart Materials and Polymers
Publisher: MDPI AG
Date: 28-05-2020
Abstract: Functional polymers show unique physical and chemical properties, which can manifest as dynamic responses to external stimuli such as radiation, temperature, chemical reaction, external force, and magnetic and electric fields [...]
Study on motion of rigid rod on a circular surface using MHPM
Publisher: Elsevier BV
Date: 09-2014
A New Strategy for Achieving Shape Memory Effects in 4D Printed Two-Layer Composite Structures
Publisher: MDPI AG
Date: 13-12-2022
Abstract: In this study, a new strategy and design for achieving a shape memory effect (SME) and 4D printed two-layer composite structures is unveiled, thanks to fused deposition modeling (FDM) biomaterial printing of commercial filaments, which do not have an SME. We used ABS and PCL as two well-known thermoplastics, and TPU as elastomer filaments that were printed in a two-layer structure. The thermoplastic layer plays the role of constraint for the elastomeric layer. A rubber-to-glass transition of the thermoplastic layer acts as a switching phenomenon that provides the capability of stabilizing the temporary shape, as well as storing the deformation stress for the subsequent recovery of the permanent shape by phase changing the thermoplastic layer in the opposite direction. The results show that ABS–TPU had fixity and recovery ratios above 90%. The PCL–TPU composite structure also demonstrated complete recovery, but its fixity was 77.42%. The difference in the SME of the two composite structures is related to the transition for each thermoplastic and programming temperature. Additionally, in the early cycles, the shape-memory performance decreased, and in the fourth and fifth cycles, it almost stabilized. The scanning electron microscopy (SEM) photographs illustrated superior interfacial bonding and part integrity in the case of multi-material 3D printing.
3D‐Printed Triboelectric Nanogenerators: State of the Art, Applications, and Challenges
Publisher: Wiley
Date: 08-02-2021
In vitro static and dynamic cell culture study of novel bone scaffolds based on 3D-printed PLA and cell-laden alginate hydrogel
Publisher: IOP Publishing
Date: 22-06-2022
Abstract: The aim of this paper was to design and fabricate a novel composite scaffold based on the combination of 3D-printed polylactic acid-based triply periodic minimal surfaces (TPMSs) and cell-laden alginate hydrogel. This novel scaffold improves the low mechanical properties of alginate hydrogel and can also provide a scaffold with a suitable pore size, which can be used in bone regeneration applications. In this regard, an implicit function was used to generate some gyroid TPMS scaffolds. Then the fused deposition modeling process was employed to print the scaffolds. Moreover, the micro computed tomography technique was employed to assess the microstructure of 3D-printed TPMS scaffolds and obtain the real geometries of printed scaffolds. The mechanical properties of composite scaffolds were investigated under compression tests experimentally. It was shown that different mechanical behaviors could be obtained for different implicit function parameters. In this research, to assess the mechanical behavior of printed scaffolds in terms of the strain–stress curves on, two approaches were presented: equivalent volume and finite element-based volume. Results of strain–stress curves showed that the finite-element based approach predicts a higher level of stress. Moreover, the biological response of composite scaffolds in terms of cell viability, cell proliferation, and cell attachment was investigated. In this vein, a dynamic cell culture system was designed and fabricated, which improves mass transport through the composite scaffolds and applies mechanical loading to the cells, which helps cell proliferation. Moreover, the results of the novel composite scaffolds were compared to those without alginate, and it was shown that the composite scaffold could create more viability and cell proliferation in both dynamic and static cultures. Also, it was shown that scaffolds in dynamic cell culture have a better biological response than in static culture. In addition, scanning electron microscopy was employed to study the cell adhesion on the composite scaffolds, which showed excellent attachment between the scaffolds and cells.
Pattern-driven 4D printing
Publisher: Elsevier BV
Date: 05-2018
A pneumatic conveyor robot for color detection and sorting
Publisher: Elsevier BV
Date: 2022
Advanced Design, Fabrication, and Applications of 3D-Printable Piezoelectric Nanogenerators
Publisher: Springer Science and Business Media LLC
Date: 05-01-2022
3D printed soft parallel actuator
Publisher: IOP Publishing
Date: 20-03-2018
Influence of post-processing CO2 laser cutting and FFF 3D printing parameters on the surface morphology of PLAs: Statistical modelling and RSM optimisation
Publisher: Elsevier BV
Date: 06-2023
3D-printed bio-inspired zero Poisson’s ratio graded metamaterials with high energy absorption performance
Publisher: IOP Publishing
Date: 21-01-2022
Abstract: This study aims at introducing a number of two-dimensional (2D) re-entrant based zero Poisson’s ratio (ZPR) graded metamaterials for energy absorption applications. The metamaterials’ designs are inspired by the 2D image of a DNA molecule. This inspiration indicates how a re-entrant unit cell must be patterned along with the two orthogonal directions to obtain a ZPR behavior. Also, how much metamaterials’ energy absorption capacity can be enhanced by taking slots and horizontal beams into account with the inspiration of the DNA molecule’s base pairs. The ZPR metamaterials comprise multi-stiffness unit cells, so-called soft and stiff re-entrant unit cells. The variability in unit cells’ stiffness is caused by the specific design of the unit cells. A finite element analysis (FEA) is employed to simulate the deformation patterns of the ZPRs. Following that, meta-structures are fabricated with 3D printing of TPU as hyperelastic materials to validate the FEA results. A good correlation is observed between FEA and experimental results. The experimental and numerical results show that due to the presence of multi-stiffness re-entrant unit cells, the deformation mechanisms and the unit cells’ densifications are adjustable under quasi-static compression. Also, the structure designed based on the DNA molecule’s base pairs, so-called structure F‴, exhibits the highest energy absorption capacity. Apart from the ersity in metamaterial unit cells’ designs, the effect of multi-thickness cell walls is also evaluated. The results show that the ersity in cell wall thicknesses leads to boosting the energy absorption capacity. In this regard, the energy absorption capacity of structure ‘E’ enhances by up to 33% than that of its counterpart with constant cell wall thicknesses. Finally, a comparison in terms of energy absorption capacity and stability between the newly designed ZPRs, traditional ZPRs, and auxetic metamaterial is performed, approving the superiority of the newly designed ZPR metamaterials over both traditional ZPRs and auxetic metamaterials.
Control-Oriented Modelling of a 3D-Printed Soft Actuator
Publisher: MDPI AG
Date: 26-12-2018
DOI: 10.3390/MA12010071
Abstract: A new type of soft actuator was developed by using hydrogel materials and three-dimensional (3D) printing technology, attracting the attention of researchers in the soft robotics field. Due to parametric uncertainties of such actuators, which originate in both a custom design nature of 3D printing as well as time and voltage variant characteristics of polyelectrolyte actuators, a sophisticated model to estimate their behaviour is required. This paper presents a practical modeling approach for the deflection of a 3D printed soft actuator. The suggested model is composed of electrical and mechanical dynamic models while the earlier version describes the actuator as a resistive-capacitive (RC) circuit. The latter model relates the ionic charges to the bending of an actuator. The experimental results were acquired to estimate the transfer function parameters of the developed model incorporating Takagi-Sugeno (T-S) fuzzy sets. The proposed model was successful in estimating the end-point trajectory of the actuator, especially in response to a broad range of input voltage variation. With some modifications in the electromechanical aspects of the model, the proposed modelling method can be used with other 3D printed soft actuators.
Experimentally validated vibro-acoustic modeling of 3D bio-printed grafts for potential use in human tympanic membrane regeneration
Publisher: Elsevier BV
Date: 03-2022
4D printing: a cutting-edge platform for biomedical applications
Publisher: IOP Publishing
Date: 26-09-2022
Abstract: Nature’s materials have evolved over time to be able to respond to environmental stimuli by generating complex structures that can change their functions in response to distance, time, and direction of stimuli. A number of technical efforts are currently being made to improve printing resolution, shape fidelity, and printing speed to mimic the structural design of natural materials with three-dimensional printing. Unfortunately, this technology is limited by the fact that printed objects are static and cannot be reshaped dynamically in response to stimuli. In recent years, several smart materials have been developed that can undergo dynamic morphing in response to a stimulus, thus resolving this issue. Four-dimensional (4D) printing refers to a manufacturing process involving additive manufacturing, smart materials, and specific geometries. It has become an essential technology for biomedical engineering and has the potential to create a wide range of useful biomedical products. This paper will discuss the concept of 4D bioprinting and the recent developments in smart materials, which can be actuated by different stimuli and be exploited to develop biomimetic materials and structures, with significant implications for pharmaceutics and biomedical research, as well as prospects for the future.
Spatial, temporal, and health associations of eating alone: A cross-cultural analysis of young adults in urban Australia and Japan
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.APPET.2017.08.013
Abstract: Eating alone is driven by social and cultural factors, not solely by in idual preferences. In academic research, eating alone is often simply treated as an alternative to social, commensal eating, and little is known about the practice of eating alone itself. This study employs a cross-cultural analysis to explore social and cultural associations of eating alone. The analysis is based on 1) cultural domain data, derived from principal component analysis of freelist responses, a set of words or phrases related to the topic of eating alone and 2) in-depth interviews with 72 young adults aged 20-40 in urban Australia and Japan. Many Australian and Japanese young adult participants associated eating alone with both pleasure and stress of being isolated from others. However, the comparison of principal components between Australian and Japanese groups and gender subgroups showed cross-cultural variations and complexity in the context of eating alone including: locations and timings of eating alone, and associations with healthy/unhealthy eating. Analyses of interviews are included to deepen understandings of cultural domains. These key associations are influenced by a range of social and cultural environments such as fast food cultures, work and life environments, and the scope of public health nutrition programs. The association between eating alone and healthy eating among young adults indicates that in idualistic understandings of food intake in current public health nutrition programs are more favorable to eating alone and foster a gap between ideas of healthy eating and commensal eating as a cultural ideal.
Development and analysis of a 3D printed hydrogel soft actuator
Publisher: Elsevier BV
Date: 10-2017
3D Printing On-Water Sports Boards with Bio-Inspired Core Designs
Publisher: MDPI AG
Date: 20-01-2020
Abstract: Modeling and analyzing the sports equipment for injury prevention, reduction in cost, and performance enhancement have gained considerable attention in the sports engineering community. In this regard, the structure study of on-water sports board (surfboard, kiteboard, and skimboard) is vital due to its close relation with environmental and human health as well as performance and safety of the board. The aim of this paper is to advance the on-water sports board through various bio-inspired core structure designs such as honeycomb, spiderweb, pinecone, and carbon atom configuration fabricated by three-dimensional (3D) printing technology. Fused deposition modeling was employed to fabricate complex structures from polylactic acid (PLA) materials. A 3D-printed s le board with a uniform honeycomb structure was designed, 3D printed, and tested under three-point bending conditions. A geometrically linear analytical method was developed for the honeycomb core structure using the energy method and considering the equivalent section for honeycombs. A geometrically non-linear finite element method based on the ABAQUS software was also employed to simulate the boards with various core designs. Experiments were conducted to verify the analytical and numerical results. After validation, various patterns were simulated, and it was found that bio-inspired functionally graded honeycomb structure had the best bending performance. Due to the absence of similar designs and results in the literature, this paper is expected to advance the state of the art of on-water sports boards and provide designers with structures that could enhance the performance of sports equipment.
Metamaterial boat fenders with supreme shape recovery and energy absorption/dissipation via FFF 4D printing
Publisher: IOP Publishing
Date: 21-08-2023
Abstract: In maritime transportation, a fender acts like a bumper to absorb the kinetic energy of a boat berthing against a jetty, pier wall, or other boats. They have high energy absorption and low reaction forces, preventing damage to boats and berthing structures. The aim of this paper is to introduce a novel conceptual design for a new class of lightweight boat-fendering systems with superior energy absorption/dissipation and shape recovery features. Different metamaterials with honeycomb, re-entrant, and re-entrant chiral auxetic patterns are designed in the form of boat fender panels, and their thermo-mechanical behaviors are analyzed experimentally and numerically. A finite element modeling (FEM) is developed to investigate the compressive behaviors of boat fenders. Some of designs are 4D printed by fused filament fabrication of shape memory polylactic acid polymers and then tested thermo-mechanically. A good correlation is observed between numerical and experimental results, supporting the FEM accuracy. Results reveal that proposed boat fenders have considerable energy absorption/dissipation along with the capability to fully recover plastic deformations by simply heating up. The excellent mechanical property recovery of the proposed boat-fendering system is also shown under cycling loadings. Due to the absence of similar conceptual designs, models, and results in the specialized literature, this paper is expected to be instrumental towards 4D printing novel boat fenders with supreme energy absorption/dissipation and shape recovery properties promoting sustainability.
Custom Shoe Sole Design and Modeling Toward 3D Printing
Publisher: AccScience Publishing
Date: 1970
Abstract: This study introduces a design procedure for improving an in idual& rsquo s footwear comfort with body weight index and activity requirements by customized three-dimensional (3D)-printed shoe midsole lattice structure. This method guides the selection of customized 3D-printed fabrications incorporating both physical and geometrical properties that meet user demands. The analysis of the lattice effects on minimizing the stress on plantar pressure was performed by initially creating various shoe midsole lattice structures designed. An appropriate common 3D printable material was selected along with validating its viscoelastic properties using finite element analysis. The lattice structure designs were analyzed under various loading conditions to investigate the suitability of the method in fabricating a customized 3D-printed shoe midsole based on the in idual& rsquo s specifications using a single material with minimum cost, time, and material use.
Functional Polymers in Sensors and Actuators: Fabrication and Analysis
Publisher: MDPI
Date: 31-08-2020
Numerical study on polymer nanofibers with electrically charged jet of viscoelastic fluid in electrospinning process
Publisher: Springer Science and Business Media LLC
Date: 10-2017
3D‐Printed Phase‐Change Artificial Muscles with Autonomous Vibration Control
Publisher: Wiley
Date: 04-05-2023
Abstract: Currently, additive manufacturing is utilized to fabricate many different actuators suited for soft robots. However, an effective controller paradigm is essential to benefit from the advantages of soft robots in terms of power consumption, production costs, weight, and safety while operating near living systems. In this work, an artificial muscle is additively manufactured with soft silicone elastomer material capable of demonstrating several levels of stiffness. The 3D‐printed muscle is equipped with carbon fibers to receive a stimulus signal and develop a programmable joint that can present different stiffnesses. A nonlinear controller is developed to autonomously control the variable stiffness joint based on a reinforcement learning algorithm. The controller exhibits a slight increase in settling time however, it demonstrates a decrease in fluctuation litude by 33% and a substantial reduction in power consumption by 41% in comparison to the optimized proportional integral derivative controller. At the same time, it is adaptable to and reliable in new conditions. The variable stiffness muscle is also used as a controllable mechanism to suppress the low frequency vibration. The study shows that the muscle can successfully attenuate the vibration autonomously when it is increased.
Active force control of 3-RRR planar parallel manipulator
Publisher: IEEE
Date: 09-2010
Bioinspired Pattern-Driven Single-Material 4D Printing for Self-Morphing Actuators
Publisher: MDPI AG
Date: 16-08-2022
DOI: 10.3390/SU141610141
Abstract: Four-dimensional (4D) printing of shape memory polymers is a leading research field due to the possibilities allowed by using these materials. The strain difference in the structures that is caused by the different stiffness profiles can be used to influence the shape-memory effect in the actuators. In this study, the influence of patterns on the strain is tested in polylactic acid (PLA) actuators using patterns made of different shapes. Five bioinspired geometrical shapes, namely, circles, squares, hexagons, rhombuses, and triangles, are used in the three-dimensional (3D) printing of the actuators. The use of shapes of different sizes along with combinations of different patterns in the PLA actuators is carried out to develop 40 actuators with different designs. The effects of the patterns and their characteristics are analysed and compared. The self-bending angles of the actuators range from 6.19° to 30.86°, depending on the patterns and arrangement used. To demonstrate the feasibility of utilizing the proposed designs in practical applications, a hand-like shaped gripper is developed. The results show that the gripper can grip objects with uniform and non-uniform cross-sections. The developed gripper demonstrates that the proposed concept can be implemented in various applications, including self-morphing structures and soft robotics.
Control-Based 4D Printing: Adaptive 4D-Printed Systems
Publisher: MDPI AG
Date: 26-04-2020
DOI: 10.3390/APP10093020
Abstract: Building on the recent progress of four-dimensional (4D) printing to produce dynamic structures, this study aimed to bring this technology to the next level by introducing control-based 4D printing to develop adaptive 4D-printed systems with highly versatile multi-disciplinary applications, including medicine, in the form of assisted soft robots, smart textiles as wearable electronics and other industries such as agriculture and microfluidics. This study introduced and analysed adaptive 4D-printed systems with an advanced manufacturing approach for developing stimuli-responsive constructs that organically adapted to environmental dynamic situations and uncertainties as nature does. The adaptive 4D-printed systems incorporated synergic integration of three-dimensional (3D)-printed sensors into 4D-printing and control units, which could be assembled and programmed to transform their shapes based on the assigned tasks and environmental stimuli. This paper demonstrates the adaptivity of these systems via a combination of proprioceptive sensory feedback, modeling and controllers, as well as the challenges and future opportunities they present.
3D printing non-assembly compliant joints for soft robotics
Publisher: Elsevier BV
Date: 09-2022
Recent progress in extrusion 3D bioprinting of hydrogel biomaterials for tissue regeneration: a comprehensive review with focus on advanced fabrication techniques
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0BM00973C
Abstract: Over the last decade, 3D bioprinting has received immense attention from research communities to bridge the ergence between artificially engineered tissue constructs and native tissues.
A Portable Non-Contact Tremor Vibration Measurement and Classification Apparatus
Publisher: MDPI AG
Date: 17-01-2022
DOI: 10.3390/ACT11010026
Abstract: Tremors are the most common type of movement disorder and affect the lives of those experiencing them. The efficacy of tremor therapies varies according to the aetiology of the tremor and its correct diagnosis. This study develops a portable measurement device capable of non-contact measurement of the tremor, which could assist in tremor diagnosis and classification. The performance of this device was assessed through a validation process using a shaker at a controlled frequency to measure human tremors, and the device was able to measure vibrations of 50 Hz accurately, which is more than twice the frequency of tremors produced by humans. Then, the device is tested to measure the tremors for two different activation conditions: rest and postural, for both hand and leg. The measured non-contact tremor vibration data successfully led to tremor classification in the subjects already diagnosed using a contact accelerometer.
Dynamic plant-derived polysaccharide-based hydrogels
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.CARBPOL.2019.115743
Abstract: Plant-derived polysaccharides are widely used to fabricate hydrogels because of their ease of gelation and functionalization, plus exceptional biological properties. As an ex le, nanocellulose is a suitable candidate to fabricate hydrogels for tissue engineering applications due to its enhanced mechanical and biological properties. However, hydrogels are prone to permanent failure whilst under load without the ability to reform their networks once damaged. Recently, considerable efforts are being made to fabricate dynamic hydrogels via installation of reversible crosslinks within their networks. In this paper, we review the developments in the design of dynamic hydrogels from plant-derived polysaccharides, and discuss their applications in tissue engineering, sensors, bioelectronics devices, etc. The main goal of the paper is to elucidate how the network design of hydrogels can influence their dynamic properties: self-healing and self-recovery. Complementary to this, current challenges and prospects of dynamic plant-derived hydrogels are discussed.
Fuzzy force learning controller of flexible wiper system
Publisher: Springer Science and Business Media LLC
Date: 07-03-2015
Bending control of a 3D printed polyelectrolyte soft actuator with uncertain model
Publisher: Elsevier BV
Date: 04-2019
Using fibrincollagen composite hydrogel and silk for bio-inspired design of tympanic membrane grafts: A vibro-acoustic analysis
Publisher: Elsevier BV
Date: 10-2021
Blood Pressure Sensors: Materials, Fabrication Methods, Performance Evaluations and Future Perspectives
Publisher: MDPI AG
Date: 11-08-2020
DOI: 10.3390/S20164484
Abstract: Advancements in materials science and fabrication techniques have contributed to the significant growing attention to a wide variety of sensors for digital healthcare. While the progress in this area is tremendously impressive, few wearable sensors with the capability of real-time blood pressure monitoring are approved for clinical use. One of the key obstacles in the further development of wearable sensors for medical applications is the lack of comprehensive technical evaluation of sensor materials against the expected clinical performance. Here, we present an extensive review and critical analysis of various materials applied in the design and fabrication of wearable sensors. In our unique transdisciplinary approach, we studied the fundamentals of blood pressure and examined its measuring modalities while focusing on their clinical use and sensing principles to identify material functionalities. Then, we carefully reviewed various categories of functional materials utilized in sensor building blocks allowing for comparative analysis of the performance of a wide range of materials throughout the sensor operational-life cycle. Not only this provides essential data to enhance the materials’ properties and optimize their performance, but also, it highlights new perspectives and provides suggestions to develop the next generation pressure sensors for clinical use.
Vat polymerization 3D printing of composite acrylate photopolymer-based coated glass beads
Publisher: IOP Publishing
Date: 08-2023
Abstract: Vat photopolymerization-based three-dimensional (3D) printing techniques have been used as an efficient method for complex and special geometries in various applications. Composites are also a group of polymer materials that are obtained by adding a reinforcing component such as filler, fibres with different origins. Therefore, the development of 3D printable composites is paramount due to their high precision and speed of production. Glass beads (GBs) have been favorites as economical reinforcement agents for their chemical stability, water resistance in acidic environments, dimensional stability, and eco-friendly properties. In this study, 3D printable composites based on coated glass beads (CGBs) have been prepared. First, the beads are coated with ultraviolet (UV) curable resins to improve the interface with the polymer matrix. Then, CGBs are mixed with 3D printing resin and formulated for digital light processing (DLP) printing. The coating process is checked by scanning electron microscopy (SEM), and the mechanical properties of the 3D-printed composite structures have been evaluated by bending and compression tests. Also, the fracture behavior of cured resin has been checked with SEM. Mechanical property investigations have shown the success of the 3D printing of the CGBs into a photopolymer resin (PR) composite with behavior modification and compatibility of the interface with the matrix in practice.
Dynamic Mussel-Inspired Chitin Nanocomposite Hydrogels for Wearable Strain Sensors
Publisher: MDPI AG
Date: 24-06-2020
Abstract: It is an ongoing challenge to fabricate an electroconductive and tough hydrogel with autonomous self-healing and self-recovery (SELF) for wearable strain sensors. Current electroconductive hydrogels often show a trade-off between static crosslinks for mechanical strength and dynamic crosslinks for SELF properties. In this work, a facile procedure was developed to synthesize a dynamic electroconductive hydrogel with excellent SELF and mechanical properties from starch olyacrylic acid (St/PAA) by simply loading ferric ions (Fe3+) and tannic acid-coated chitin nanofibers (TA-ChNFs) into the hydrogel network. Based on our findings, the highest toughness was observed for the 1 wt.% TA-ChNF-reinforced hydrogel (1.43 MJ/m3), which is 10.5-fold higher than the unreinforced counterpart. Moreover, the 1 wt.% TA-ChNF-reinforced hydrogel showed the highest resistance against crack propagation and a 96.5% healing efficiency after 40 min. Therefore, it was chosen as the optimized hydrogel to pursue the remaining experiments. Due to its unique SELF performance, network stability, superior mechanical, and self-adhesiveness properties, this hydrogel demonstrates potential for applications in self-wearable strain sensors.
Direct 3D printing of a two-part silicone resin to fabricate highly stretchable structures
Publisher: Springer Science and Business Media LLC
Date: 16-03-2023
DOI: 10.1007/S40964-023-00421-Y
Abstract: The direct ink writing (DIW) method of 3D-printing liquid resins has shown promising results in various applications such as flexible electronics, medical devices, and soft robots. A cost-effective extrusion system for a two-part high-viscous resin is developed in this article to fabricate soft and immensely stretchable structures. A static mixer capable of evenly mixing two viscous resins in an extremely low flow regime is designed based on the required mixing performance through a series of biphasic computational fluid dynamics analyses. The printing parameters of the extrusion system are determined empirically, and the mechanical properties of the printed s les are compared to their molded counterparts. Furthermore, some potential applications of the system in soft robotics and medical training are demonstrated. This research provides a clear guide for utilizing DIW to 3D print highly stretchable structures.
Unbalance and Harmonic disturbance attenuation of a flexible shaft with active magnetic bearings
Publisher: Elsevier BV
Date: 08-2019
Vitrimer chemistry for 4D printing formulation
Publisher: Elsevier BV
Date: 10-2023
4D Printing of Smart Magnetic-Based Robotic Materials
Publisher: CRC Press
Date: 13-09-2023
Silicon-based soft parallel robots 4D printing and multiphysics analysis
Publisher: IOP Publishing
Date: 11-2022
Abstract: Four-dimensional printing has set the stage for a new generation of soft robotics. The applications of rigid planar parallel robotic manipulators are also significant because of their various desirable characteristics, such as lower inertia, higher payload, and high accuracy. However, rigid planar parallel robots are heavy and require different actuators and components. This study introduces a novel technique to produce a light three degrees of freedom soft parallel manipulator at a low cost, which can be stimulated easily. This technique allows researchers to customize the actuator’s design based on the requirement. The robot is made by 3D printing based on fused deposition modelling and a direct ink writing process. The design, development, and additive manufacturing of a soft parallel robot electrothermally driven by a linear silicon-based actuator and polylactic acid parts are presented. Silicon-based soft actuators replace the rigid conventional linear actuators in this study to drive the planar parallel manipulator. The actuation of actuators is conducted using simple heating compared to the conventional rigid actuator. Various heating approaches and configurations are compared and analysed to find the most suitable one for the effective linear stroke of the soft actuator. The finite element model is used to analyse the performance of the electrothermally silicon-ethanol soft actuators in ABAQUS. The kinematics of the planar parallel robotic manipulator are simulated in MATLAB to achieve its workspace. The final soft parallel robot mechanism and the active and passive links are fabricated and tested experimentally.
A Multi-objective, active fuzzy force controller in control of flexible wiper system
Publisher: FapUNIFESP (SciELO)
Date: 2014
Influence of Hybridization on Tensile Behaviors of Non-Absorbable Braided Polymeric Sutures
Publisher: MDPI AG
Date: 19-03-2020
Abstract: This paper aims to investigate the effects of fiber hybridization technique on the mechanical behaviors of non-absorbable braided composite sutures. Fifteen types of hybrid braided sutures (HBSs) made of polyester (PET), polypropylene (PP), and polyamide 6 (PA6) are produced and tested to measure ultimate tensile strength (UTS), maximum strain, elastic modulus, and breaking toughness. Based on the results, it is observed that the suture material plays a significant role in the tensile and mechanical performance of HBSs, and they can be tailored through the different combinations of yarns according to the required mechanical properties. Experiments exhibit occurrence positive hybrid effect in both maximum strain and elastic modulus, and negative hybrid effect in UTS. The optimal tensile performance is associated with the hybrid structure comprising 75% PA6-12.5% PET-12.5% PP. This means the ternary structure with higher PA6 content along with PP and PET, demonstrates a synergistic effect. Thus, such a ternary composite structure is very promising for the design of novel non-absorbable sutures. Due to the absence of similar results in the specialized literature, this paper is likely to advance the state-of-the-art composite non-absorbable sutures and contribute to a better understanding of the hybridization concept for optimizing composite material systems.
Bast Fiber Reinforced Green Polymer Composites: A Review on Their Classification, Properties, and Applications
Publisher: Informa UK Limited
Date: 19-08-2021
3D/4D-printed bending-type soft pneumatic actuators: fabrication, modelling, and control
Publisher: Informa UK Limited
Date: 03-08-2020
3D-Printed Programmable Mechanical Metamaterials for Vibration Isolation and Buckling Control
Publisher: MDPI AG
Date: 02-06-2022
DOI: 10.3390/SU14116831
Abstract: Vibration isolation performance at low-frequency ranges before resonance is a vital characteristic that conventional springs cannot exhibit. This paper introduces a novel zero Poisson’s ratio graded cylindrical metamaterial to fulfill two main goals: (1) vibration isolation performance in low-frequency bands prior to resonance and (2) global buckling control of a long cylindrical tube. For this purpose, “soft and stiff” re-entrant unit cells with varying stiffness were developed. The cylindrical metamaterials were then fabricated using a multi-jet fusion HP three-dimensional (3D) printer. The finite element analyses (FEA) and experimental results demonstrate that the simultaneous existence of multi-stiffness unit cells leads to quasi-zero stiffness (QZS) regions in the force-displacement relationship of a cylindrical metamaterial under compression. They possess significant vibration isolation performance at frequency ranges between 10 and 30 Hz. The proposed multi-stiffness re-entrant unit cells also offer global buckling control of long cylindrical tubes (with a length to diameter ratio of 3.7). The simultaneous existence of multi-stiffness re-entrant unit cells provides a feature for designers to adjust and control the deformation patterns and unit cells’ densification throughout cylindrical tubes.
Thermal and hydrodynamic analysis of a conducting nanofluid flow through a sinusoidal wavy channel
Publisher: Elsevier BV
Date: 12-2021
A Bioinspired Compliant 3D-Printed Soft Gripper
Publisher: Mary Ann Liebert Inc
Date: 08-2022
Abstract: A compliant three-dimensional (3D)-printed soft gripper is designed based on the bioinspired spiral spring in this study. The soft gripper is then 3D-printed using a suitable thermoplastic filament material to deliver the desired performance. The sensorless mechanism introduced in this study provides adequate compliance with a single linear actuator for interacting with delicate objects, such as manipulation of human biological materials and fruit picking. The kinematic and dynamic models of the monolithic gripper are derived analytically as well as by means of finite element analysis to synthesize its functionality. The fabricated gripper module is installed on a robot arm to demonstrate the efficacy of design for picking and placing fruits without damaging them. The presented mechanism could be customized and used in the medical and agricultural sectors with erse geometry objects.
Finite element modeling of shape memory polyurethane foams for treatment of cerebral aneurysms
Publisher: Springer Science and Business Media LLC
Date: 25-12-2024
DOI: 10.1007/S10237-021-01540-7
Abstract: In this paper, a thermo-mechanical analysis of shape memory polyurethane foams (SMPUFs) with aiding of a finite element model (FEM) for treating cerebral aneurysms (CAs) is introduced. Since the deformation of foam cells is extremely difficult to observe experimentally due to their small size, a structural cell-assembly model is established in this work via finite element modeling to examine all-level deformation details. Representative volume elements of random equilateral Kelvin open-cell microstructures are adopted for the cell foam. Also, a user-defined material subroutine (UMAT) is developed based on a thermo-visco-elastic constitutive model for SMPUFs, and implemented in the ABAQUS software package. The model is able to capture thermo-mechanical responses of SMPUFs for a full shape memory thermodynamic cycle. One of the latest treatments of CAs is filling the inside of aneurysms with SMPUFs. The developed FEM is conducted on patient-specific basilar aneurysms treated by SMPUFs. Three sizes of foams are selected for the filling inside of the aneurysm and then governing boundary conditions and loadings are applied to the foams. The results of the distribution of stress and displacement in the absence and presence of the foam are compared. Due to the absence of similar results in the specialized literature, this paper is likely to fill a gap in the state of the art of this problem and provide pertinent results that are instrumental in the design of SMPUFs for treating CAs.
4D Printing Self-Morphing Structures
Publisher: MDPI AG
Date: 25-04-2019
DOI: 10.3390/MA12081353
Abstract: The main objective of this paper is to introduce complex structures with self-bending/morphing/rolling features fabricated by 4D printing technology, and replicate their thermo-mechanical behaviors using a simple computational tool. Fused deposition modeling (FDM) is implemented to fabricate adaptive composite structures with performance-driven functionality built directly into materials. Structural primitives with self-bending 1D-to-2D features are first developed by functionally graded 4D printing. They are then employed as actuation elements to design complex structures that show 2D-to-3D shape-shifting by self-bending/morphing. The effects of printing speed on the self-bending/morphing characteristics are investigated in detail. Thermo-mechanical behaviors of the 4D-printed structures are simulated by introducing a straightforward method into the commercial finite element (FE) software package of Abaqus that is much simpler than writing a user-defined material subroutine or an in-house FE code. The high accuracy of the proposed method is verified by a comparison study with experiments and numerical results obtained from an in-house FE solution. Finally, the developed digital tool is implemented to engineer several practical self-morphing/rolling structures.
Closed-loop 4D-printed soft robots
Publisher: Elsevier BV
Date: 03-2020
4D printing soft robots guided by machine learning and finite element models
Publisher: Elsevier BV
Date: 09-2021
Magneto‐/ electro‐responsive polymers toward manufacturing, characterization, and biomedical/ soft robotic applications
Publisher: Elsevier BV
Date: 03-2022
System identification and robust tracking of a 3D printed soft actuator
Publisher: IOP Publishing
Date: 07-06-2019
Related Organisations
Deakin University - Geelong Campus At Waurn Ponds
Location: Australia
Related Funding Activities
Discovery Early Career Researcher Award - Grant ID: DE240100960
Start Date: 11-2024
End Date: 10-2027
Amount: $420,198.00
Funder: Australian Research Council
View Funded Activity