A5080137851- Advanced MEMS and NEMS Technologies
- Acoustic Wave Resonator Technologies
- Photonic and Optical Devices
- Ultrasonics and Acoustic Wave Propagation
- Electrowetting and Microfluidic Technologies
- Piezoelectric Actuators and Control
- Advanced Sensor and Energy Harvesting Materials
- Mechanical and Optical Resonators
- GaN-based semiconductor devices and materials
- Analytical Chemistry and Sensors
- Ferroelectric and Piezoelectric Materials
- Nanofabrication and Lithography Techniques
- Metal and Thin Film Mechanics
- Microfluidic and Bio-sensing Technologies
- Acoustic Wave Phenomena Research
- Gas Sensing Nanomaterials and Sensors
- Flow Measurement and Analysis
- Conducting polymers and applications
- 3D IC and TSV technologies
- Speech and Audio Processing
- Dielectric materials and actuators
- Image and Signal Denoising Methods
- Electronic Packaging and Soldering Technologies
- Underwater Acoustics Research
- Electrospun Nanofibers in Biomedical Applications
Institute of Microelectronics
2021-2025
Agency for Science, Technology and Research
2021-2025
UNSW Sydney
2015-2022
Association for Asian Studies
2021
Ming Chi University of Technology
2014
The use of Polyvinylidene Fluoride (PVDF) based piezoelectric nanofibers for sensing and actuation has been reported widely in the past. However, most cases, PVDF nanofiber mats have used applications. This work fundamentally characterizes a single electrospun demonstrates its application as element nanoelectromechanical sensors (NEMS). were spun by far field electrospinning (FFES) process complete material characterization was conducted means scanning electron microscope (SEM) imaging,...
Abstract This work demonstrates the application of electrospun single and bundled carbon nanofibers (CNFs) as piezoresistive sensing elements in flexible ultralightweight sensors. Material, electrical, nanomechanical characterizations were conducted on CNFs to understand effect critical synthesis parameter—the pyrolyzation temperature morphological, structural, electrical properties. The mechanism conductive path change under influence external stress was hypothesized explain behavior...
This paper presents the design and modeling of a novel piezoelectrically driven micro-lens actuator capable delivering large out-of-plane displacement with low driving voltage fast speed. The architecture, parameter optimization, testing are presented. consists six unimorph piezoelectric beams operating in d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">31</sub> mode to symmetrically displace holding platform. methodology exploits film...
This work presents a promising microfabrication technique employing the silicon-on-nothing (SON) process to form <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2\ \mu\mathrm{m}$</tex> thick continuous monocrystalline silicon membrane over vacuum cavity of xmlns:xlink="http://www.w3.org/1999/xlink">$1\ in depth. Utilizing SON process, high fill-factor piezoelectric micromachined ultrasonic transducer (pMUT) arrays on an 8-inch wafer with widths...
Ultrasonic ranging with piezoelectric micromachined ultrasonic transducers (pMUTs) can be used in applications such as robotic systems and industrial machinery for precise distance measurements. This work presents a technique of operating pMUTs below the resonance frequency to obtain wide bandwidth high resolution time-of-flight (ToF) ranging. Digital signal processing was performed remove residual ringing at recover wideband echo by bandpass filtering cross-correlation domain. The ToF then...
This letter presents experimental results showing significant enhancement in the dynamic performance of a novel piezoelectric micro-lens actuator using robust feedback resonant controller. The design controller is based on experimentally identified model actuator. stability closed-loop system proven by negative imaginary theory. show that resonance peak and settling time are reduced 27 dB to 2.5 ms from 119 ms, respectively. Such improvement demonstrates capability for fast auto-focus...
Fourier Transform (FT) is one of the most extensively used scientific computations for signal/image processing. Recently, an emerging highly efficient ultrasonic wavefront computing (WFC) technique was developed to compute Fast (FFT) physically using bulk acoustic wave (BAW) piezoelectric transducers and a Fresnel lens. Typically, cuboid shapes are BAW model WFC system. However, shape such usually non-uniformly tapered due fabrication process. In this paper, we investigate effect different...
We report preliminary wafer-level measurement results of air-coupled phase vapor deposition (PVD) PZT pMUTs for ranging applications recently fabricated in our Lab-in-Fab 8-inch line. Dual-port PVD designed to resonate the 100kHz range were based on a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{2\mu} \mathbf{m}$</tex> - thick film xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{4\mu}\mathbf{m}$</tex> -thick silicon...
This letter reports the application of ultra-high vacuum E-beam evaporated polysilicon (UHVEEPoly) film for lead zirconate titanate (PZT)-based piezoelectric micro-electromechanical systems (MEMSs) first time. The UHVEEPoly is employed as a passive structural layer in unimorph cantilever micro-actuators to demonstrate its applicability PZT-based MEMS. Two sets PZT micro-cantilever actuators have been fabricated and characterized this letter. set has 4-μm-thick while second made 4 μm thick...
The design, fabrication, and testing of a novel piezoelectrically driven microlens actuator with large stroke low driving voltage is presented. device fabricated on 6 μm thick ultra-high vacuum e-beam evaporated polysilicon film as the structural platform, which enables cost reduction design flexibility in comparison to devices SOI wafers. annulus platform actuated by six independently d31 unimorph PZT-based beams. has measured out-of-plane displacement 145 at 100 kV/cm (22 V) resonant...
Due to the ever-growing demands for scalable, high-efficiency, and parallel processing of high-performance computing, more research has turned its attention analog computing approach, such as acoustic systems or ultrasonic wavefront accelerators. Such a system requires heterogeneous integration different modules fabricated separately. Here, we present study various bonding materials typically used thermo-compression, eutectic, sintering techniques that are CMOS compatible suitable bulk wave...
We report preliminary wafer-level measurement results of air-coupled <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{S}\mathrm{c}_{0.15}\mathrm{A}\mathrm{l}_{0.85}\mathrm{N}$</tex> pMUTs recently fabricated in our Lab-in-Fab 8-inch line. In this work, we show that the xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{K}_{\mathrm{t}}{}^{2}$</tex> and mechanical performance devices are correlated to resonant frequency connection film...
A 2-dimensional discrete Fourier transform (2-D DFT) is a required preprocessing step for convolutional neural networks (CNNs) to perform matrix multiplication in layers. Here we present an ultrasonic wavefront-based architecture CNNs that harness the wave propagation diffraction physic (FT) effectively. The computation improved O(N) compare Fast (FFT) with O(N(log<inf>2</inf>N). In addition, analysis of proposed wavefront scheme described this paper.
This work demonstrates the imaging capabilities of a silicon-on-nothing (SON) ScAlN piezoelectric micromachined ultrasonic transducer (pMUT) array by method transmit beamforming followed suitable signal postprocessing for 3-D image reconstruction. A 2.7-MHz pMUT with 15% scandium-doped aluminum nitride (ScAlN) as piezo thin film was implemented this demonstration. total <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math...