Daniel Ssu-Han Chen

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Daniel Ssu-Han verified their affiliation via an institutional email.

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• PhD
• Senior Scientist at Agency for Science, Technology and Research (A*STAR)

Advancements in ultrasonic imaging sensors (UISs), such as improvements in cost-effectiveness, low power consumption, and suitability for challenging environments, have been useful for drone navigation. However, existing microelectromechanical systems (MEMS) transducer arrays suffer from limitations due to the non-uniform stress distribution of the...

This work presents an experimental comparative analysis of acoustic performance for series and parallel connected piezoelectric micromachined ultrasonic transducers (PMUTs) designed and fabricated in physical vapor deposition (PVD) lead zirconate titanate (PZT) and 20% scandium (Sc)-doped aluminum nitride (AlN). The aim of this research is to provi...

This article presents a novel method for close-range, high-resolution ultrasonic time-of-flight (ToF) ranging using piezoelectric micromachined ultrasonic transducers (PMUTs) operating below the device resonance in air. The proposed method involves cross correlation techniques to accurately detect the reflected echo signals despite the presence of...

This work demonstrates the imaging capabilities of a silicon-on-nothing (SON) ScAlN piezoelectric micromachined ultrasonic transducer (pMUT) array by a method of transmit beamforming followed by suitable signal postprocessing for 3-D image reconstruction. A 2.7-MHz pMUT array with 15% scandium-doped aluminum nitride (ScAlN) as the piezo thin film w...

MEMS based piezoelectrically driven micro-lens actuator experiences resonance frequency shift with changing actuation voltage and exhibits low level of damping. In this paper, we present the design and experimental implementation of a resonant controller, robust against the variation in dynamics, to enhance the damping at the first resonance freque...

This paper presents the design and implementation of a robust resonant controller to damp the first resonant mode of a MEMS-based multi-layered prestressed piezoelectric (PZT) cantilever beam. The cantilever dynamics for control design are identified from experimentally measured data. The controller design is based on a mixed negative-imaginary, pa...

This letter presents experimental results showing significant enhancement in the dynamic performance of a novel piezoelectric micro-lens actuator using a robust feedback resonant controller. The design of the feedback controller is based on experimentally identified model of the micro-lens actuator. The stability of the closed-loop system is proven...

This work demonstrates the application of electrospun single and bundled carbon nanofibers (CNFs) as piezoresistive sensing elements in flexible and ultralightweight sensors. Material, electrical, and nanomechanical characterizations were conducted on the CNFs to understand the effect of the critical synthesis parameter—the pyrolyzation temperature...

This paper presents the fabrication and characterization of a high performance piezoelectrically driven micro-lens actuator. The fabrication method involves controlling the residual stresses in the structure to predefine the initial deflection of the actuator, resulting in a larger actuation stroke. The residual stress control exploits the unique p...

This paper presents the design and modeling of a novel piezoelectrically driven micro-lens actuator capable of delivering large out-of-plane displacement with a low driving voltage and fast speed. The design architecture, parameter optimization, modeling and testing of the actuator are presented. The actuator consists of six unimorph piezoelectric...

Chapter 3 presents a comprehensive review of the various biomimetic self-powered and low-powered MEMS pressure and flow sensors that take inspiration from the biological flow sensors found in the marine world. The sensing performance of the biological flow sensors in marine animals has inspired engineers and scientists to develop efficient state-of...

http://pericles.ipaustralia.gov.au/ols/auspat/applicationDetails.do?applicationNo=2018903188

This work reports the use of graphitized Polyacrylonitrile (PAN) nanofiber bundle for strain sensing applications. Strain sensors employing piezoresistive properties of carbon nanofiber is relatively new compared to conventional piezoelectric electrospun nanofiber based devices. The graphitization of PAN nanofiber bundles annealed at 500°C, 750°C,...

The use of Polyvinylidene Fluoride (PVDF) based piezoelectric nanofibers for sensing and actuation has been reported widely in the past. However, in most cases, PVDF piezoelectric nanofiber mats have been used for sensing applications. This work fundamentally characterizes a single electrospun PVDF nanofiber and demonstrates its application as a se...

For the first time, a bimorph thin film lead zirconate titanate (PZT) micro-Actuator with thick polysilicon as a passive structural layer is reported. A simple micro-cantilever actuator consisting of 1000 μm long and 250 μm wide with 4 μm thick polysilicon structure flanked by a piezoelectric active layer on the top and bottom side has been fabrica...

This paper studies the dynamic behavior of a piezoelectric micro-lens actuator driven by a feedback system. The feedback system consists of the actuator in the forward path and an optical displacement sensor and a 90o phase shifter multiplied by a gain as feedback elements. The piezo-electric micro-lens actuator is fabricated and characterized for...

This letter reports the application of ultra-high vacuum E-beam evaporated polysilicon (UHVEEPoly) film for lead zirconate titanate (PZT)-based piezoelectric micro-electro-mechanical systems (MEMSs) for the first time. The UHVEEPoly film is employed as a passive structural layer in unimorph piezoelectric cantilever micro-actuators to demonstrate it...

This paper describes an efficient fiber to submicron silicon waveguide coupling based on an inversely tapered silicon waveguide embedded in a SiO2 waveguide that is suspended in air. The inverse taper waveguide consist of a 50um long and 240nm thick silicon that linearly taper in width from 500nm to 120nm, which is embedded in SiO2. The SiO2 wavegu...