ORCID Profile
0000-0002-1636-2132
Current Organisation
Monash University
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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)
Interdisciplinary Engineering | Composite and Hybrid Materials | Nanoscale Characterisation | Biomechanical Engineering | Materials Engineering | Membrane and Separation Technologies | Fluidisation and Fluid Mechanics | Chemical Characterisation of Materials
ANZSRC Socio-Economic Objective (SEO)
Related Links
Publications
On-demand sample injection: combining acoustic actuation with a tear-drop shaped nozzle to generate droplets with precise spatial and temporal control
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9LC00837C
Abstract: An on-demand droplet injection method for controlled delivery of nanolitre-volume liquid s les to scientific instruments for subsequent analysis is presented.
Controlled particle self-assembly in an evaporating droplet
Publisher: Elsevier BV
Date: 03-2012
An all-in-one nanoreactor for high-resolution microscopy on nanomaterials at high pressures
Publisher: IEEE
Date: 2011
A Monte-Carlo simulation of the effect of surface morphology on the fracture of nanobeams
Publisher: Springer Science and Business Media LLC
Date: 11-2007
Hopf Bifurcation in a Disk-Shaped NEMS
Publisher: ASMEDC
Date: 2003
DOI: 10.1115/DETC2003/VIB-48516
Abstract: Self-sustained mechanical vibrations of a disc-type microfabricated resonator were experimentally observed when a continuous wave (CW) laser beam was focused on the periphery of the disc (for a 40 μm diameter resonator, natural frequency 0.89MHz, the laser power above a 250 W threshold was required). A theoretical model for self-oscillatory behavior has been developed based on FEM analysis of a stress pattern created within the resonator by the focused laser beam. This model accounts for the fact that the amount of absorbed laser light is modulated due to the motion of the resonator through the optical interferometric pattern. Analytical study reveals the presence of a Hopf-type bifurcation with a critical laser power close to the experimentally observed value. Harmonic balance analysis indicates the existence of a stable limit cycle in the phase plane determining the litude of self-oscillations.
Ultrafast star-shaped acoustic micromixer for high throughput nanoparticle synthesis
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9LC01174A
Abstract: Ultrafast acoustic micromixers can effectively homogenize fluids in 4 milliseconds, at 8 ml min −1 flowrates providing a 50-fold improvement in throughput.
High throughput acoustic microfluidic mixer controls self-assembly of protein nanoparticles with tuneable sizes
Publisher: Elsevier BV
Date: 03-2021
Microfluidic plug steering using surface acoustic waves
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5LC00468C
Abstract: A microfluidic chip capable of steering and unevenly splitting plugs at a Y-junction uses surface acoustic waves.
Limit cycle oscillations in CW laser-driven NEMS
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2004
Vibrating membrane with discontinuities for rapid and efficient microfluidic mixing
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5LC00836K
Abstract: A vibrating membrane with discontinuities in the form of through holes is utilised to achieve millisecond mixing.
Microelectronic 3D Imaging and Neuromorphic Recognition for Autonomous UAVs
Publisher: Springer Netherlands
Date: 2020
Particle separation using virtual deterministic lateral displacement (vDLD)
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3LC51367J
Abstract: Sorting of particles measuring 6.6 μm and 7.0 μm has been achieved in a scheme in which lateral displacement is deterministic.
Micro-fabricated channel with ultra-thin yet ultra-strong windows enables electron microscopy under 4-bar pressure
Publisher: AIP Publishing
Date: 20-02-2012
DOI: 10.1063/1.3688490
Abstract: Transmission electron microscopy (TEM) of (de-)hydrogenation reactions is crucial to characterize efficiency of hydrogen storage materials. The nanoreactor, a micromachined channel with 15-nm-thick windows, effectively confines the gas flow to an electron-transparent chamber during TEM of reactions. Realistic experiments require very high pressures to be sustained by the device. Nanomechanical bulge tests and simulations show that due to a very strong size effect, ultra-thin device components can reliably withstand tensile stresses as high as 19.5 GPa enabling high pressure operation. We use the device to characterize Pd particles under a 4-bar H2 pressure within the ultra-high-vacuum of the TEM.
Droplet control technologies for microfluidic high throughput screening (μHTS)
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7LC00005G
Abstract: This review analyses state-of-the-art droplet control technologies that exhibit potential to be used in the new generation of screening devices.
Particle Manipulation in the Presence of Fluid Interfaces
Publisher: Research Publishing Services
Date: 05-2013
Surface acoustic wave enabled pipette on a chip
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6LC01318J
Abstract: Presented here is an automated microfluidic platform, pipette on a chip, capable of selectively pipetting subs les from mobile droplets in the picoliter range with high accuracy using a non-contact approach. The system utilizes acoustic forces, is modular and robust allowing integration with existing lab on a chip devices.
Effect of surface morphology on the fracture strength of silicon nanobeams
Publisher: AIP Publishing
Date: 28-08-2006
DOI: 10.1063/1.2338649
Abstract: The effect of nanoscale surface morphology on the fracture strength of 190-nm-thick, doubly cl ed Si beams was measured experimentally. The surface morphology was controlled through aqueous etching and characterized by atomic force microscopy. The beams fractured along the primary cleavage planes, {111}. Fracture strength was extracted using finite element simulations of the experiment. Nanobeams etched with relatively smooth morphologies (0.4nm rms) were able to sustain a tensile stress of 15.8GPa, close to theoretical strengths predicted by previous atomistic calculations. In contrast, nanobeams decorated with nanometer-high step bunches (1.5nm rms) had a 20% lower fracture strength, 12.8GPa, suggesting that careful attention to processing is necessary for maximum strength.
In situ synthesis of silver nanowire gel and its super-elastic composite foams
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0NR03958F
Abstract: A very convenient one-pot strategy to fabricate highly porous silver gels via the in situ synthesis of silver nanowires (AgNW).
Using nano-mechanics and surface acoustic wave (SAW) for disease monitoring and diagnostics at a cellular level in red blood cells
Publisher: Elsevier BV
Date: 2015
Graphene elastomer electrodes for medical sensing applications: Combining high sensitivity, low noise and excellent skin compatibility enabling continuous medical monitoring
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2020
Particle trapping in a capillary tube
Publisher: IEEE
Date: 10-2012
The importance of travelling wave components in standing surface acoustic wave (SSAW) systems
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6LC00798H
Abstract: The dominant forcing mechanism for particle manipulation using SSAW is shown to be spatially dependent when travelling components are considered.
Particle manipulation using an ultrasonic micro-gripper
Publisher: AIP Publishing
Date: 15-10-2012
DOI: 10.1063/1.4759127
Abstract: We show that ultrasonic micro-grippers, 100 μm high segmented circular structures actuated with piezoelectric elements, can be used to establish a localised resonant pressure field within a fluid droplet, and hence allow effective manipulation of silica microspheres independently from the global boundaries of the fluid volume. We demonstrate through experiments and simulations that despite variations in the fluid shape and location, the method achieves particle clustering in consistent locations at fixed operating frequencies.
Characterization of ultrathin membranes to enable TEM observation of gas reactions at high pressures
Publisher: ASMEDC
Date: 2010
Abstract: In-situ, atomic scale imaging of chemical reactions at high gas pressures and elevated temperatures is crucial to characterize structural changes in catalysts. To enable transmission electron microscopy (TEM) imaging in realistic environments, a MEMS device that confines the gas flow and reactions to a micromachined channel was developed. The device consists of two parts that were brought into contact to form a channel. At the central part of the structure there is a large square region containing several 10–15 nm thick membranes that act as electron transparent windows, hence, allowing TEM imaging. The present design was previously demonstrated to sustain 0.1 MPa pressure, yet, to accurately mimic industrial conditions, the device should survive gas pressures as high as 1 MPa. In this article, we study the mechanical performance of in idual components using simulations and nanoscale bulge tests and determine the necessary modifications to improve device functionality.
Synthesis of CsPbBr3 perovskite nanocrystals with acoustically actuated millisecond mixing
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0TC04519E
Abstract: Improved morphology and size homogeneity of CsPbBr 3 perovskite nanocrystals synthesised at low-temperature through highly efficient acoustic mixing in a microfluidic platform.
Detecting Subtle Vibrations Using Graphene-Based Cellular Elastomers
Publisher: American Chemical Society (ACS)
Date: 27-03-2017
Abstract: Ultralight graphene elastomer-based flexible sensors are developed to detect subtle vibrations within a broad frequency range. The same device can be employed as an accelerometer, tested within the experimental bandwidth of 20-300 Hz as well as a microphone, monitoring sound pressures from 300 to 20 000 Hz. The sensing element does not contain any metal parts, making them undetectable by external sources and can provide an acceleration sensitivity of 2.6 mV/g, which is higher than or comparable to those of rigid Si-based piezoresistive microelectromechanical systems (MEMS).
The role height plays in the spreading of liquid droplets over sharp edges
Publisher: AIP Publishing
Date: 28-01-2013
DOI: 10.1063/1.4789990
Abstract: We show that the volume which can be held on the top of a pillar is dependent on the elevation of the pillar. When a spreading fluid encounters an edge between two inclined surfaces, the angle between them determines the hysteresis at the edge. To examine the changes in the hysteresis as a function of pillar height, circular pillars of various heights ranging from 31.8 μm down to 200 nm were fabricated in silicon. It was found that as the height is reduced below 7.2 μm there is a marked and almost linear decline in the hysteresis offered by the pillar edge.
Nanofluidic and monolithic environmental cells for cryogenic microscopy
Publisher: IOP Publishing
Date: 24-12-2019
Abstract: We present a device capable of combining nanofluidics and cryogenic transmission electron microscopy (cryo-TEM) to allow inspection of water-soluble s les under near-native conditions. The devices can be produced in a multitude of designs, but as a general rule, they consist of channels or chambers enclosed between two electron-transparent silicon nitride windows. With the appropriate design, those devices can allow screening of multiple s les in parallel and remove the interaction between the s le and the environment (no air-water interface). We demonstrate channel sizes from 80 to 500 nm in height and widths from 100 to 2000 μm. The presented fabrication flow allows producing hollow devices on a single wafer eliminating the need of aligning or bonding two half-cavities from separate wafers, which provides additional resistance to thermal stress. Taking advantage of a single-step through-membrane exposure with a 100 keV electron beam, we introduced arrays of thin (10-15 nm) electron-transparent silicon nitride membrane windows aligned between top and bottom (200-250 nm) carrier membranes. Importantly, the final devices are compatible with standard TEM holders. Furthermore, they are compatible with rapid freezing of s les, which is crucial for the formation of vitreous water, hence avoiding the formation of crystalline ice, that is detrimental for TEM imaging. To demonstrate the potential of this technology, we tested those devices in imaging experiments verifying their applicability for cryo-TEM applications and proved that vitreous water could be prepared through conventional plunge freezing of the chips.
Fabrication of AlN slender piezoelectric cantilevers for highspeed MEMS actuations
Publisher: Elsevier BV
Date: 2011
An ultra-portable, self-contained point-of-care nucleic acid amplification test for diagnosis of active COVID-19 infection
Publisher: Springer Science and Business Media LLC
Date: 26-07-2021
DOI: 10.1038/S41598-021-94652-0
Abstract: There is currently a high level of demand for rapid COVID-19 tests, that can detect the onset of the disease at point of care settings. We have developed an ultra-portable, self-contained, point-of-care nucleic acid lification test for diagnosis of active COVID-19 infection, based on the principle of loop mediated isothermal lification (LAMP). The LAMP assay is 100% sensitive and specific to detect a minimum of 300 RNA copies/reaction of SARS-CoV-2. All of the required s le transportation, lysing and lification steps are performed in a standalone disposable cartridge, which is controlled by a battery operated, pocket size (6x9x4cm 3 ) unit. The test is easy to operate and does not require skilled personnel. The total time from s le to answer is approximately 35 min a colorimetric readout indicates positive or negative results. This portable diagnostic platform has significant potential for rapid and effective testing in community settings. This will accelerate clinical decision making, in terms of effective triage and timely therapeutic and infection control interventions.
Droplet Manipulation Using Acoustic Streaming Induced by a Vibrating Membrane
Publisher: American Chemical Society (ACS)
Date: 09-05-2016
DOI: 10.1021/ACS.ANALCHEM.5B04481
Abstract: We present a simple method for on-demand manipulation of aqueous droplets in oil. With numerical simulations and experiments, we show that a vibrating membrane can produce acoustic streaming. By making use of this vortical flow, we manage to repulse the droplets away from the membrane edges. Then, by simply aligning the membrane at 45° to the flow, the droplets can be forced to follow the membrane's boundaries, thus steering them across streamlines and even between different oil types. We also characterize the repulsion and steering effect with various excitation voltages at different water and oil flow rates. The maximum steering frequency we have achieved is 165 Hz. The system is extremely robust and reliable: the same membrane can be reused after many days and with different oils and/or surfactants at the same operating frequency.
Tuning the oxygen functional groups in reduced graphene oxide papers to enhance the electromechanical actuation
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5RA09743F
Abstract: Tuning oxygen content in rGO paper is found to enhance its actuation strain. The developed theoretical model and in-depth experimental investigation show that capacitance and stiffness are two key factors in the actuation mechanism of rGO papers.
Microfluidic on-demand droplet merging using surface acoustic waves
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4LC00456F
Abstract: Digital microfluidic chip merges multiple consecutive droplets (nl) selectively and controllably using surface acoustic waves.
Surface acoustic waves for on-demand production of picoliter droplets and particle encapsulation
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3LC50372K
Abstract: Microscopic water-in-oil droplets are a versatile chemical and biological platform whose dimensions result in short reaction times and require minuscule amounts of reagent. Methods exist for the production of droplets, though the vast majority are only able to do so in continuous flows, restricting the ability to independently control reactions of in idual droplets, a prerequisite for programmable digital microfluidics. Here we present a novel method to produce in idual picoliter-scale droplets on-demand using surface acoustic waves (SAW). Acoustic forces arising from SAW act on the oil-water interface, creating a droplet whose volume is defined by the applied power, duration of the force and system geometry. Additionally, this method is able to pre-concentrate particles simultaneously with droplet production, meaning that particles and cells, even if in a dilute mixture, can be easily encapsulated. Our method is expected to be applicable to high-throughput screening, bioreactor creation and other microfluidic processes.
On-chip droplet production regimes using surface acoustic waves
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5LC01341K
Abstract: Aqueous droplets suspended in an immiscible carrier fluid are a key tool in microfluidic chemical analysis platforms.
Microfluidic Processing of Ligand-Engineered NiO Nanoparticles for Low-Temperature Hole-Transporting Layers in Perovskite Solar Cells
Publisher: Wiley
Date: 28-06-2021
Abstract: Nickel oxide (NiO) is used as a hole‐transporting layer (HTL) in perovskite solar cells (PSCs) because of its high optical transmittance, intrinsic p‐type doping, and suitable valence band energy level. However, fabricating high‐quality NiO films typically requires high‐temperature annealing, which limits their applicability for low‐temperature, printable PSCs. Herein, the need for such postprocessing steps is circumvented by coupling 4‐hydroxybenzoic acid (HBA) or trimethyloxonium tetrafluoroborate (Me 3 OBF 4 ) ligand‐modified NiO nanoparticles (NPs) with a Tesla‐valve microfluidic mixer to deposit high‐quality NiO films at a temperature °C. The NP dispersions and the resulting thin films are thoroughly characterized using a combination of optical, structural, thermal, chemical, and electrical methods. While the optical and structural properties of the ligand‐exchanged NiO NPs remain comparable with those possessing the native long‐chained aliphatic ligands, the ligand‐modified NiO thin films exhibit dramatic reductions in surface energy and an increase in hole mobilities. These are correlated with concomitant and significant enhancements in performance and stability factors of PSCs when the ligand‐modified NiO NPs are used as HTL layers within p−i−n device architectures.
Microfluidics Based Generation of Curcumin Loaded Microfibrous Mat against Staphylococcus aureus Biofilm by Photodynamic Therapy
Publisher: American Chemical Society (ACS)
Date: 13-02-2023
Force-compensating MEMS sensor for AFM cantilever stiffness calibration
Publisher: IEEE
Date: 11-2014
Reliability of Nanostructures
Publisher: Springer Netherlands
Date: 2012
Continuous flow ultrasonic particle trapping in a glass capillary
Publisher: AIP Publishing
Date: 03-02-2014
DOI: 10.1063/1.4863645
Abstract: Ultrasonic manipulation devices frequently exploit ultrasonic standing waves to trap particles in locations across the width of a fluidic channel or chamber. In contrast, this work describes a device, which traps particles along the length of the channel and hence at different locations along the direction of fluid flow. Actuation is achieved using a single piezoelectric transducer bonded to a borosilicate glass capillary, which defines the fluidic channel. Modes of operation have been found experimentally and through use of finite element simulation methods in which the particles can be trapped at locations away from the piezoelectric transducer allowing optimal visual access to the clumps of particles. These locations are separated by distances significantly greater than half the acoustic wavelength. When flow is introduced, a single clump is formed and optical access is unhindered by the opaque transducer allowing a method of capturing particles for multi-axial optical analysis. Applications could include determination of s le concentration or creation of concentrated s les for subsequent batch operations.
Nanoscale displacement sensing using microfabricated variable-inductance planar coils
Publisher: AIP Publishing
Date: 30-09-2013
DOI: 10.1063/1.4823828
Abstract: Microfabricated spiral inductors were employed for nanoscale displacement detection, suitable for use in implantable pressure sensor applications. We developed a variable inductor sensor consisting of two coaxially positioned planar coils connected in series to a measurement circuit. The devices were characterized by varying the air gap between the coils hence changing the inductance, while a Colpitts oscillator readout was used to obtain corresponding frequencies. Our approach shows significant advantages over existing methodologies combining a displacement resolution of 17 nm and low hysteresis (0.15%) in a 1 × 1 mm2 device. We show that resolution could be further improved by shrinking the device's lateral dimensions.
Zero displacement microelectromechanical force sensor using feedback control
Publisher: AIP Publishing
Date: 14-04-2014
DOI: 10.1063/1.4871380
A Comparative Study of the Strength of Si, SiN and SiC used at Nanoscales
Publisher: Springer Science and Business Media LLC
Date: 2007
DOI: 10.1557/PROC-1052-DD06-31
Abstract: Microelectromechanical systems (MEMS) are being used in many critical applications that require very high stress levels. To properly design MEMS components, mechanical properties should be characterized testing relevant sized s les that are fabricated with the same procedures as the final structure. In this paper we use atomic force microscopy (AFM) experiments to study the fracture strength statistics of polycrystalline SiC and SiN nanobeams, and compare their mechanical performance with the performance of previously tested Si nanostructures. Using the same AFM method and similar s le shape and sizes, allows a direct comparison to be made, which will be useful in determining the best material for different mechanical applications and also to validate the theoretical limits.
Characterization of adhesive properties of red blood cells using surface acoustic wave induced flows for rapid diagnostics
Publisher: AIP Publishing
Date: 08-09-2014
DOI: 10.1063/1.4895472
Abstract: This letter presents a method which employs surface acoustic wave induced acoustic streaming to differentially peel treated red blood cells (RBCs) off a substrate based on their adhesive properties and separate populations of pathological cells from normal ones. We demonstrate the principle of operation by comparing the applied power and time required to overcome the adhesion displayed by healthy, glutaraldehyde-treated or malaria-infected human RBCs. Our experiments indicate that the method can be used to differentiate between various cell populations contained in a 9 μl droplet within 30 s, suggesting potential for rapid diagnostics.
X-ray compatible microfluidics for in situ studies of chemical state, transport and reaction of light elements in an aqueous environment using synchrotron radiation
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1LC00996F
Abstract: This paper presents an X-ray compatible microfluidic platform for in situ characterisation of chemical reactions at synchrotron light sources.
Ultrasensitive Strain Sensor Produced by Direct Patterning of Liquid Crystals of Graphene Oxide on a Flexible Substrate
Publisher: American Chemical Society (ACS)
Date: 17-08-2016
Abstract: Ultrasensitive flexible strain sensors were developed through the combination of shear alignment of a high concentration graphene oxide (GO) dispersion with fast and precise patterning of multiple rectangular features on a flexible substrate. Resistive changes in the reduced GO films were investigated under various uniaxial strain cycles ranging from 0.025 to 2%, controlled with a motorized nanopositioning stage. The devices uniquely combine a very small detection limit (0.025%) and a high gauge factor with a rapid fabrication process conducive to batch production.
A MEMS capacitive pH sensor for high acidic and basic solutions
Publisher: IEEE
Date: 11-2014
Stability of flowing open fluidic channels
Publisher: AIP Publishing
Date: 02-2013
DOI: 10.1063/1.4792940
Abstract: Open fluidic systems have a distinct advantage over enclosed channels in that the fluids exposed nature makes for easy external interaction, this finds uses in introduction of s les by adding liquid droplets or from the surrounding gaseous medium. This work investigates flowing open channels and films, which can potentially make use of the open section of the system as an external interface, before bringing the s le into an enclosed channel. Clearly, in this scenario a key factor is the stability of the flowing open fluid. The open channels investigated include a straight open channel defined by a narrow strip of solid surface, the edges of which allow large contact angle hysteresis, and a wider structure allowing for multiple inputs and outputs. A model is developed for fluid flow, and the findings used to describe the process of failure in both cases.
In-situ TEM on (de)hydrogenation of Pd at 0.5–4.5 bar hydrogen pressure and 20–400°C
Publisher: Elsevier BV
Date: 2012
DOI: 10.1016/J.ULTRAMIC.2011.10.010
Abstract: We have developed a nanoreactor, s le holder and gas system for in-situ transmission electron microscopy (TEM) of hydrogen storage materials up to at least 4.5 bar. The MEMS-based nanoreactor has a microheater, two electron-transparent windows and a gas inlet and outlet. The holder contains various O-rings to have leak-tight connections with the nanoreactor. The system was tested with the (de)hydrogenation of Pd at pressures up to 4.5 bar. The Pd film consisted of islands being 15 nm thick and 50-500 nm wide. In electron diffraction mode we observed reproducibly a crystal lattice expansion and shrinkage owing to hydrogenation and dehydrogenation, respectively. In selected-area electron diffraction and bright/dark-field modes the (de)hydrogenation of in idual Pd particles was followed. Some Pd islands are consistently hydrogenated faster than others. When thermally cycled, thermal hysteresis of about 10-16°C between hydrogen absorption and desorption was observed for hydrogen pressures of 0.5-4.5 bar. Experiments at 0.8 bar and 3.2 bar showed that the (de)hydrogenation temperature is not affected by the electron beam. This result shows that this is a fast method to investigate hydrogen storage materials with information at the nanometer scale.
Ultrafast Dynamic Piezoresistive Response of Graphene‐Based Cellular Elastomers
Publisher: Wiley
Date: 02-11-2015
Abstract: Ultralight graphene-based cellular elastomers are found to exhibit nearly frequency-independent piezoresistive behaviors. Surpassing the mechanoreceptors in the human skin, these graphene elastomers can provide an instantaneous and high-fidelity electrical response to dynamic pressures ranging from quasi-static up to 2000 Hz, and are capable of detecting ultralow pressures as small as 0.082 Pa.
Open microdroplet diluter for concentration-gradient generation
Publisher: IOP Publishing
Date: 10-07-2014
Single line particle focusing using a vibrating bubble
Publisher: AIP Publishing
Date: 10-11-2014
DOI: 10.1063/1.4901951
Abstract: In this study, we present a method for fine focusing of microparticles using a vibrating air bubble. Fluorescent polystyrene particles of 2.01 and 6.60 μm are shown to be focused along the edge of a 50-μm-wide channel. The mechanism is determined to be shear stresses caused by the boundary layer on the vibrating gas/liquid meniscus. Experiments show that the focussing region width reduces with higher excitation litude, focusing is not as sensitive towards the flow rate as the excitation frequency, and there is an optimal bubble radius. Finally, we show that red blood cells and 6.60 μm particles can be focused into what is effectively a single line.
The particle valve: On-demand particle trapping, filtering, and release from a microfabricated polydimethylsiloxane membrane using surface acoustic waves
Publisher: AIP Publishing
Date: 21-07-2014
DOI: 10.1063/1.4891424
Abstract: We introduce a surface acoustic wave (SAW) based method for acoustically controlled concentration, capture, release, and sorting of particles in a microfluidic system. This method is power efficient by the nature of its design: the vertical direction of a traveling acoustic wave, in which the majority of the energy at the SAW-water interface is directed, is used to concentrate particles behind a microfabricated polydimethylsiloxane membrane extending partially into a channel. Sorting is also demonstrated with this concentration shown to be size-dependent. Low-power, miniature SAW devices, using methods such as the one demonstrated here, are well placed for future integration into point-of-care diagnostic systems.
Shell-type micromechanical oscillator
Publisher: SPIE
Date: 25-04-2003
DOI: 10.1117/12.499107
A star shaped acoustofluidic mixer enhances rapid malaria diagnostics via cell lysis and whole blood homogenisation in 2 seconds
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2LC00195K
Abstract: Shear stresses generated by a silicon resonator embedded inside a microfluidic channel can rapidly and effectively lyse cells and homogenise whole blood. This significantly improves sensitivity of ATR-FTIR spectroscopy based diagnostic tests.
Contactless tracking of humans using non-contact triboelectric sensing technology: Enabling new assistive applications for the elderly and the visually impaired
Publisher: Elsevier BV
Date: 12-2021
Non-contact acoustic trapping in circular cross-section glass capillaries: A numerical study
Publisher: Acoustical Society of America (ASA)
Date: 11-2012
DOI: 10.1121/1.4754547
Abstract: Ultrasonic particle manipulation has many applications in microfluidic systems. Such manipulation is achievable by establishing an ultrasonic standing wave in fluid filled micromachined chambers. In this work, the focus is on analyzing the trapping potential of water filled capillary tubes actuated ultrasonically. The curved walls necessitate the use of a finite element modeling approach. Multiple arrangements of the piezoelectric transducers were studied along with the effects of changing the capillary and piezoelectric transducer thicknesses. Additionally, different modes of driving the piezoelectric transducers were investigated. It was found that positioning four piezoelectric transducers equally spaced around the capillary tube provided the best force potential field for trapping polystyrene spheres in the center of the capillary.
Acoustically enhanced microfluidic mixer to synthesize highly uniform nanodrugs without the addition of stabilizers
Publisher: Informa UK Limited
Date: 03-2018
DOI: 10.2147/IJN.S153805
A microfabricated fringing field capacitive pH sensor with an integrated readout circuit
Publisher: AIP Publishing
Date: 02-06-2014
DOI: 10.1063/1.4881263
Abstract: This work presents a microfabricated fringe-field capacitive pH sensor using interdigitated electrodes and an integrated modulation-based readout circuit. The changes in capacitance of the sensor result from the permittivity changes due to pH variations and are converted to frequency shifts using a crossed-coupled voltage controlled oscillator readout circuit. The shift in resonant frequency of the readout circuit is 30.96 MHz for a change in pH of 1.0–5.0. The sensor can be used for the measurement of low pH levels, such as gastric acid, and can be integrated with electronic pills. The measurement results show high repeatability, low noise, and a stable output.
Haemoprocessor: A Portable Platform Using Rapid Acoustically Driven Plasma Separation Validated by Infrared Spectroscopy for Point-of-Care Diagnostics
Publisher: MDPI AG
Date: 14-02-2022
DOI: 10.3390/BIOS12020119
Abstract: The identification of biomarkers from blood plasma is at the heart of many diagnostic tests. These tests often need to be conducted frequently and quickly, but the logistics of s le collection and processing not only delays the test result, but also puts a strain on the healthcare system due to the sheer volume of tests that need to be performed. The advent of microfluidics has made the processing of s les quick and reliable, with little or no skill required on the user’s part. However, while several microfluidic devices have been demonstrated for plasma separation, none of them have validated the chemical integrity of the s le post-process. Here, we present Haemoprocessor: a portable, robust, open-fluidic system that utilizes Travelling Surface Acoustic Waves (TSAW) with the expression of overtones to separate plasma from 20× diluted human blood within a span of 2 min to achieve 98% RBC removal. The plasma and red blood cell separation quality/integrity was validated through Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy and multivariate analyses to ascertain device performance and reproducibility when compared to centrifugation (the prevailing gold-standard for plasma separation). Principal Component Analysis (PCA) showed a remarkable separation of 92.21% between RBCs and plasma components obtained through both centrifugation and Haemoprocessor methods. Moreover, a close association between plasma isolates acquired by both approaches in PCA validated the potential of the proposed system as an eminent cell enrichment and plasma separation platform. Thus, compared to contemporary acoustic devices, this system combines the ease of operation, low s le requirement of an open system, the versatility of a SAW device using harmonics, and portability.
Methyl monolayers improve the fracture strength and durability of silicon nanobeams
Publisher: AIP Publishing
Date: 04-12-2006
DOI: 10.1063/1.2400180
Abstract: Monolayer-thick coatings have a significant effect on the fracture strength and durability of 210-nm-thick, smooth (∼0.4nm rms roughness), single crystal silicon nanobeams. The initial Weibull fracture strength of beams terminated with a methyl (CH3) monolayer was 18.2GPa. This strength did not degrade after a 23-day exposure to air. In contrast, beams terminated with a monolayer of hydrogen atoms were initially weaker than methyl-terminated beams, and their strength degraded rapidly in air. After a 23-day air exposure, the strength of H-terminated beams was reduced by at least 30%. Since strength durability is correlated with the oxidation resistance of the monolayers, the degradation of H-terminated beams is attributed to the formation of oxide nuclei that act as local stress concentrators.
Feedback-Controlled MEMS Force Sensor for Characterization of Microcantilevers
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2015
Acoustic Resonator Optimisation for Airborne Particle Manipulation
Publisher: Elsevier BV
Date: 2015
Related Organisations
London Centre For Nanotechnology
Location: United Kingdom of Great Britain and Northern Ireland
Related Funding Activities
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE180100090
Start Date: 2018
End Date: 06-2019
Amount: $1,136,244.00
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE140100085
Start Date: 2015
End Date: 12-2015
Amount: $300,000.00
Funder: Australian Research Council
View Funded Activity