ORCID Profile
0000-0003-0102-5958
Current Organisation
Deakin University - Geelong Campus at Waurn Ponds
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Publisher: Informa UK Limited
Date: 02-07-2016
Publisher: MDPI AG
Date: 16-11-2020
Abstract: The demands for wearable technologies continue to grow and novel approaches for powering these devices are being enabled by the advent of new energy materials and novel manufacturing strategies. In addition, decreasing the energy consumption of portable electronic devices has created a huge demand for the development of cost-effective and environment friendly alternate energy sources. Energy harvesting materials including piezoelectric polymer with its special properties make this demand possible. Herein, we develop a flexible and lightweight nanogenerator package based on polyvinyledene fluoride (PVDF)/LiCl electrospun nanofibers. The piezoelectric performance of the developed nanogenator is investigated to evaluate effect of the thickness of the as-spun mat on the output voltage using a vibration and impact test. It is found that the output voltage increases from 1.3 V to 5 V by adding LiCl as additive into the spinning solution compared with pure PVDF. The prepared PVDF/LiCl nanogenerator is able to generate voltage and current output of 3 V and 0.5 μA with a power density output of 0.3 μW cm−2 at the frequency of 200 Hz. It is found also that the developed nanogenerator can be utilized as a sensor to measure temperature changes from 30 °C to 90 °C under static pressure. The developed electrospun temperature sensor showed sensitivity of 0.16%/°C under 100 Pa pressure and 0.06%/°C under 220 Pa pressure. The obtained results suggested the developed energy harvesting textiles have promising applications for various wearable self-powered electrical devices and systems.
Publisher: Wiley
Date: 12-10-2015
DOI: 10.1002/PEN.24192
Publisher: SAGE Publications
Date: 09-2013
Publisher: MedCrave Group, LLC
Date: 08-11-2017
Publisher: IOP Publishing
Date: 12-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0TA00227E
Abstract: Recent advances in smart textiles and wearable technologies based on piezoelectric fibers as wearable energy harvesters.
Publisher: Wiley
Date: 16-02-2020
Publisher: Wiley
Date: 28-05-2023
Abstract: Polymeric gel‐based artificial muscles exhibiting tissue‐matched Young's modulus (10 Pa–1 MPa) promise to be core components in future soft machines with inherently safe human–machine interactions. However, the ability to simultaneously generate fast, large, high‐power, and long‐lasting actuation in the open‐air environment, has yet been demonstrated in this class of ultra‐soft materials. Herein, to overcome this hurdle, the design and synthesis of a twisted and coiled liquid crystalline glycerol‐organogel (TCLCG) is reported. Such material with a low Young's modulus of 133 kPa can surpass the actuation performance of skeletal muscles in a variety of aspects, including actuation strain (66%), actuation rate (275% s −1 ), power density (438 kW m −3 ), and work capacity (105 kJ m −3 ). Notably, its power density is 14 times higher than the record of state‐of‐the‐art polymeric gels. No actuation performance degradation is detected in the TCLCG even after air exposure for 7 days, owing to the excellent water retention ability enabled by glycerol as co‐solvent with water. Using TCLCG, mobile soft robots with extraordinary maneuverability in unstructured environments are successfully demonstrated, including a crawler showing fast bidirectional locomotion (0.50 mm s −1 ) in a small‐confined space, and a roller that can escape after deep burying in sand.
Publisher: Informa UK Limited
Date: 09-2015
Publisher: Springer International Publishing
Date: 2022
Publisher: Wiley
Date: 07-04-2023
Abstract: Recent advances in wearable energy harvesting technology as solutions to occupational health and safety programs are presented. Workers are often exposed to harmful conditions—especially in the mining and construction industries—where chronic health issues can emerge over time. While wearable sensors technology can aid in early detection and long‐term exposure tracking, powering them and the associated risks are often an impediment for their widespread use, such as the need for frequent charging and battery safety. Repetitive vibration exposure is one such hazard, e.g., whole body vibration, yet it can also provide parasitic energy that can be harvested to power wearable sensors and overcome the battery limitations. This review can critically analyze the vibration effect on workers’ health, the limitations of currently available devices, explore new options for powering different personal protective equipment devices, and discuss opportunities and directions for future research. The recent progress in self‐powered vibration sensors and systems from the perspective of the underlying materials, applications, and fabrication techniques is reviewed. Lastly, the challenges and perspectives are discussed for reference to the researchers who are interested in self‐powered vibration sensors.
Publisher: Wiley
Date: 04-12-2022
Abstract: Carbon nanotube‐spandex textiles are rapidly gaining in popularity as sensors for human motion, yet their use as—and comparison to—viable clinical‐based instrumentation has not been thoroughly investigated. Herein, the use of novel yarn‐based sensors that show excellent characteristics, ideal for joint kinematic sensing, is described. Knee kinematic monitoring of nine healthy participants while walking on a treadmill is examined. This is enabled through a 3D‐printed knee brace integrated with a wireless transmission device. The design, development, and testing of the wearable device is presented along with wireless data capture and processing. Additionally, the findings are compared in vivo to those reported by a reference optoelectronic measurement system (KneeKG) for validation purposes. The results show a high correlation between both systems, with an average Pearson's r ‐value of 0.89 across each corresponding knee. This study is the first to explore the use of these novel yarn sensors for sagittal knee kinematic monitoring on participants during trials and validate the findings via an optoelectronic measurement system.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8TA10964H
Abstract: A new strategy of a triaxial architecture based on piezoelectric fibers, silver coated nylon and braiding technology as a wearable energy harvesting generator.
Publisher: Informa UK Limited
Date: 05-09-2013
Publisher: Informa UK Limited
Date: 05-03-2017
Publisher: MDPI AG
Date: 21-12-2020
DOI: 10.3390/APP10249143
Abstract: The applications of tissue engineered constructs have witnessed great advances in the last few years, as advanced fabrication techniques have enabled promising approaches to develop structures and devices for biomedical uses. (Bio-)printing, including both plain material and cell/material printing, offers remarkable advantages and versatility to produce multilateral and cell-laden tissue constructs however, it has often revealed to be insufficient to fulfill clinical needs. Indeed, three-dimensional (3D) (bio-)printing does not provide one critical element, fundamental to mimic native live tissues, i.e., the ability to change shape roperties with time to respond to microenvironmental stimuli in a personalized manner. This capability is in charge of the so-called “smart materials” thus, 3D (bio-)printing these biomaterials is a possible way to reach four-dimensional (4D) (bio-)printing. We present a comprehensive review on stimuli-responsive materials to produce scaffolds and constructs via additive manufacturing techniques, aiming to obtain constructs that closely mimic the dynamics of native tissues. Our work deploys the advantages and drawbacks of the mechanisms used to produce stimuli-responsive constructs, using a classification based on the target stimulus: humidity, temperature, electricity, magnetism, light, pH, among others. A deep understanding of biomaterial properties, the scaffolding technologies, and the implant site microenvironment would help the design of innovative devices suitable and valuable for many biomedical applications.
Publisher: Wiley
Date: 06-12-2020
Abstract: The ubiquity of wearables, coupled with the increasing demand for power, presents a unique opportunity for fiber‐based mobile energy generator systems. However, no commercially available systems currently exist with typical problems including low energy efficiency short cycle life slow and expensive manufacturing and stiff, heavy or bulky componentry that reduce wearer comfort and aesthetic appeal. Herein, a new method is demonstrated to create wearable energy generators and sensors using nanostructured hybrid polyvinylidene fluoride (PVDF)/reduced graphene oxide (rGO)/barium‐titanium oxide (BT) piezoelectric fibers and exploiting the enormous variety of textile architectures. Highly stretchable piezoelectric fibers based on coiled PVDF/rGO/BT fibers energy generator and sensor are developed. It is found that the coiled PVDF/ rGO/BT enables to stretch up to ≈100% strain that produces a peak voltage output of ≈1.3 V with a peak power density of 3 W Kg −1 which is 2.5 times higher than previously reported for piezoelectric textiles. An energy conversion efficiency of 22.5% is achieved for the coiled hybrid piezofiber energy generator. A prototype energy generator and sensors based on a hybrid piezofibers wearable device for energy harvesting and monitoring real time precise healthcare are demonstrated.
Publisher: SAGE Publications
Date: 12-2011
DOI: 10.1177/155892501100600404
Abstract: Nowadays, the mechanical characterization of 3-D spacer fabrics has attracted the interest of many textile researchers. These Spacer fabrics present special mechanical and physical characteristics compared to conventional textiles due to their wonderful porous 3-D structures. These fabrics, produced by warp knitting method, have extensive application in automobile, locomotive, aerospace, building and other industries. In these applications, the compressibility behaviour plays a significant role in the fabric structural stability. This compressibility behaviour could be affected by different knitting parameters such as density of pile yarn, fabric thickness, texture design etc. The aim of this paper is to introduce and develop an appropriate elastic theoretical model to predict the compressibility behaviour of warp knitted spacer fabric (WKSF). Three theoretical models are proposed, based on modelling pile yarns as the curved bars and are improved in three steps: a) with same curvatures in weft and warp directions (model A), b) curved bar for warp direction and cantilever bar for weft direction (model B), and c) curved bars with two different curvatures in weft and warp directions considering the curvature variations under loading (model C: improved model). The results obtained by the proposed models have been compared with previous model based on simply cantilever bars theory in literature. The results show that the simulation data obtained by the model C are closer to the experimental results comparing to the models A and B. Model C based on different weave parameters could better predict the elastic compressibility behaviour of this kind of WKSF in order to compare with previous models.
Publisher: MDPI AG
Date: 23-08-2021
DOI: 10.3390/NANO11082153
Abstract: Piezoelectric fibers have an important role in wearable technology as energy generators and sensors. A series of hybrid nanocomposite piezoelectric fibers of polyinylidene fluoride (PVDF) loaded with barium–titanium oxide (BT) and reduced graphene oxide (rGO) were prepared via the melt spinning method. Our previous studies show that high-performance fibers with 84% of the electroactive β-phase in the PVDF generated a peak output voltage up to 1.3 V and a power density of 3 W kg−1. Herein, the dynamic mechanical and creep behavior of these fibers were investigated to evaluate their durability and piezoelectric performance. Dynamic mechanical analysis (DMA) was used to provide phenomenological information regarding the viscoelastic properties of the fibers in the longitudinal direction. DSC and SEM were employed to characterize the crystalline structure of the s les. The storage modulus and the loss tangent increased by increasing the frequency over the temperature range (−50 to 150 °C) for all of the fibers. The storage modulus of the PVDF/rGO nanocomposite fibers had a higher value (7.5 GPa) in comparison with other fibers. The creep and creep recovery behavior of the PVDF/nanofillers in the nanocomposite fibers have been explored in the linear viscoelastic region at three different temperatures (10–130 °C). In the PVDF/rGO nanocomposite fibers, strong sheet/matrix interfacial interaction restricted the mobility of the polymer chains, which led to a higher modulus at temperatures 60 and 130 °C.
Publisher: Wiley
Date: 04-04-2023
Abstract: The first solid‐state engine that converted heat into continuous mechanical motion using a thermally responsive actuating material was introduced almost a century ago. These engines used vulcanized rubber where the cyclically heating and cooling of the rubber generate continuous mechanical power in pendulum or wheel type engines. The development of solid‐state heat engines has seen several waves of activity with interest stimulated by the introduction of new actuating materials capable of responding to different environmental stimuli. Opportunities for improved engine outputs are afforded by recently developed artificial muscle materials. A theoretical connection between engine output and the characteristics of the actuator material is developed to compare the performances of vulcanized rubber, shape memory alloys (SMAs), and twisted and coiled polymer (TCP) fiber artificial muscles. It is shown that with an engine designed to suit the actuation performance of TCPs engines powered by the tensile actuation of such materials would exceed the output of SMA heat engines. The properties needed in actuator materials to further enhance engine output are identified and polymer structures that may produce such properties are described.
Publisher: Informa UK Limited
Date: 14-07-2016
Location: Australia
Location: Iran (Islamic Republic of)
No related grants have been discovered for Fatemeh Mokhtari.