ISPE 2021 - November 12-14, 2021

Title of Plenary Speech
Micro-LED Technology Development

Abstract of Plenary Speech
The talk is to introduce the developing of microLED technology for display applications. There is a great improvement in the MicroLED technology. They contain the epilayer structure, processing, mass transferring, repairing and characteristic measurements. In this talk, two kinds of GaN-based microLEDs and related devices performance will be discussed. One in very mature blue GaN LEDs and another is new GaInN-based red light microLEDs. Even thy can be fabricated into microLEDs, there exist some defects and needed processing to repair them. After, the fabricated module microLEDs and related problems will be described. The technology trend will also be mentioned in this talk.

Distinguished Prof. Ying-Hao Chu
Department of Material Science and Engineering

National Yang Ming Chiao Tung University, Taiwan

Title of Keynote Speech

MICAtronics for flex sensors

Abstract of Keynote Speech

A new world is being formed based on the technologies composed of artificial intelligence, Internet of Things (IoT), and robots. Especially, in the research fields of IoT and robotics systems, a device with mechanical flexibility can deliver more degrees of freedom as far as the design aspects are concerned. Therefore, the development of soft and flexible electronics becomes an important research direction for wearable and IoT devices. Due to the mechanical flexibility, polymer materials and thin metal foils are commonly used in the fabrication of flexible electronic systems. However, the reliability issue under practical operations hinders the applications of these flexible electronics, especially for those on polymer based substrates. This is attributed to a mismatch of thermal expansion coefficient between substrate and functional materials or low thermal and chemical endurance of polymers and organic materials. A lot of researchers are working hard and together to expand the applicability of current flexible devices. However, new pathway to flexible electronics can also be developed in parallel to provide more subtle solutions, thus in need of new platform to integrate functional materials with good thermal and chemical stabilities together with mechanical flexibility. In this research field, oxides can play an important role due to their intriguing functionalities and superior thermal and chemical stabilities. To deliver high-quality thin films or structures based on oxides, heteroepitaxy is essential. However, the lack of a suitable approach remains an obstacle for flexible oxide heteroepitaxy. van der Waals epitaxy (vdWE) involving two-dimensional layered materials can play a crucial role in the expansion of thin film epitaxy by overcoming the bottleneck of material combinations due to lattice/thermal matching conditions inherent to conventional epitaxy. In this study, we use a 2D material as the substrate. In this talk, we confine ourselves to the validity of vdWE of functional oxides on muscovite mica throughout this treatise. With such demonstrations, it is anticipated that MICAtronics, vdWE on mica, can reveal unusual properties and emergent phenomena in the realm of high-performance flexible device applications.

Invited Speakers

Prof. Bhaskar Kanseri
Department of Physics, Indian Institute of Technology Delhi,India

Title of Invited Talk

Quantum state engineering for science and technology applications

Abstract of Invited Talk

Engineering quantum states of light finds applications in several areas, such as in quantum communication and information technologies, in Quantum sensing and metrology, in fundamental testing etc. Quantum states such as single and entangled photons need to be generated at high rates along with best possible purity and fidelity for implementation in several quantum technologies and use of resonant optical cavities can help us in achieving high rates. The synchronized pulse optical cavities refer to those optical resonators which operate in pulsed regime and thus are having well defined mode properties in time domain. They may be used for fast generation of few photon Fock states and could also work as a short-time memory device, storing a weak pulse containing few photons for timescales ranging from several nanoseconds to several milliseconds. One can employ synchronized pulse optical cavities to approximate as an on-demand quantum source, for Fock state generation and realization of all cavity Schrödinger cat state for quantum information applications. In this talk, use of such cavities for single and few -photon Fock state generation and for quantum memories would be demonstrated. The talk further aims to highlight some of our attempts towards realizing methods for secure quantum communication through free space and optical fibres. A lab realization of differential phase shift QKD protocol would be demonstrated using 2.5 GHz rate laser pulses. Our study also focuses to explore the effects of partial coherence of pump on spatial profile and polarization entanglement features of biphotons. Photon beams having partially spatially coherent features can be more robust against atmospheric losses and turbulence compared to their fully coherent counterparts, offering a way to achieve higher key rates in quantum communication applications.

Prof. Ngoc Dang Khoa Tran
Faculty of Mechanical Engineering
Industrial University of Ho Chi Minh City, Vietnam

Title of Invited Talk

Design Compliant Bistable Gripper with Multiple Contact Points in Jaws

Abstract of Invited Talk

A new design of a compliant gripper is described that employed the bistable structure and the jaws with multiple contact points to grip and release the object. The benefit of the mechanism is free energy in the gripping action and increase the steady force holding. The investigation of the nonlinear behavior of the mechanism is estimated with the high value in minimum force compared with the maximum force to improve the gripping force. The contact force of the jaws is analyzed with many dimensions of the objects. Moreover, the dimension of the jaws is optimized to keep the objects by strong robustness. The finite element method is implemented to predict the motion characteristic and verify the maximum stress in the mechanism. A prototype is fabricated by the 3D printed method. The mechanism can work with a circular object with a maximum diameter is 75 mm. The mechanism has potential in many applications such as robotic, medical, agricultural and micro mechanism system.

Prof. Teeranoot Chanthasopeephan
Biological Engineering, King Mongkut's University of Technology Thonburi, Thailand

Title of Invited Talk

Applied 3-PRS Parallel Manipulator for Stabilizing Platform: Kinematics and Control

Abstract of Invited Talk

In this paper, a 3-PRS (prismatic, revolute, and spherical) parallel manipulator for platform stabilization is designed. The main purpose of this device is to stabilize visual equipment, which is placed on top of a car to inspect electrical transmission cables as part of routine maintenance. Due to the bulky and heavy infrared cameras used during inspections, a stabilizer platform has been designed to handle the weight of camera equipment up to 10 kg. This device consists of two major mechanisms. The first mechanism is able to adjust the angle of the camera. Thus, the user can focus the camera along the electric transmission lines. The second mechanism is for stabilization. The mechanism serves to stabilize the orientation and position of the camera in roll, pitch, and heave directions. To test the performance of the stabilization mechanism, the device is fed with the known value of the angle as regards input. As such, the device is trying to compensate for the change in angle. Results show that errors between input angles and compensated angles are in the range of 0.4-3%. Errors are seen to be within an acceptable range. It is significant that the resultant errors do not affect the orientation of the camera.

Prof. Hieng Kiat Jun
Department of Mechanical and Material Engineering
Universiti Tunku Abdul Rahman, Malaysia

Title of Invited Talk

Semiconductor Quantum Dot-sensitized Solar Cell: Challenges and Opportunities

Abstract of Invited Talk

Nanosized semiconductors have been demonstrated as viable sensitizers for the application of quantum dot-sensitized solar cells (QDSSC). These solar cells have much research interest in the past few years due to the excellent optical properties of the nanosized semiconductor sensitizers and the high performance produced by the solar cells. Generally, QDSSC works on the same principle as the dye-sensitized solar cell where quantum dot (QD) sensitizers such as semiconductor PbS, CdS or CdSe are used instead of the usual inorganic dye sensitizers. To date, QDSSCs have reached a power conversion efficiency of 15%. However, most of the reported high efficiency QDSSCs are Cd- or Pb-based. In order to elevate the application of emerging solar cell technologies in the mainstream photovoltaic market, low-cost, stable and non-toxic materials are crucial for the development of solar cell modules. Non-toxic QD sensitizers are usually termed as lead-free or cadmium-free materials. In this short review, "green" sensitizers are reviewed. Among the "green" materials that have been adopted as sensitizers in QDSSC included Sn- and Bi-based compounds. Although the performances of "green" QDSSCs such as Ag₂S and Bi₂S₃ QDSSCs are not as high as that of CdS or CdSe based QDSSCs, their performance can be enhanced with post-thermal annealing, carbon doping and the application of passivation layer. The effect of these techniques are discussed in the context of performance and fabrication techniques.

Prof. Chengkuo Lee
Department of Electrical and Computer Engineering
National University of Singapore, Singapore

Title of Invited Talk

AIoT based Sensing Technology for Future Smart Homes and Cities

Abstract of Invited Talk

With the high-speed data transmission capability enabled by the 5G wireless communication network, people have envisioned the Internet of Things (IoT) system towards smart homes and cities where numerous interrelated electronic devices are linked together in a vast and complicated network. The surging artificial intelligence (AI) technologies push forward the development of diversified smart sensors used at the smart homes in order to realize the advanced artificial intelligence of things (AIoT) technology. The human machine interfaces (HMI) have been improved from tactile sensors, such as touchpads and joysticks, to now including the accurate detection of dexterous body movements in more diversified and sophisticated sensors. In this talk, we discuss a few triboelectric based HMIs including gloves, socks, soft robotic manipulator, and exoskeleton for object recognition, gaming, VR/AR applications, rehabilitation, and digital twin applications. Besides, a smart floor monitoring system is reported with the merits of low cost and high scalability for smart home applications.

Prof. Yu-Lin Shen
Department of Mechanical Engineering
University of New Mexico, U.S.A.

Title of Invited Talk

Evolution of Wrinkle Patterns on Soft Substrate-Attached Thin Films-Direct Numerical Predictions

Abstract of Invited Talk

Surface wrinkling instability on thin films attached to a compliant substrate is a well-recognized form of deformation, which can develop under mechanical or thermal loading. Surface wrinkling in engineering systems has traditionally been viewed as a form of damage. Researchers in recent years, however, have increasingly exploited mechanical instabilities to create surface patterns with desirable optical, electronic, mechanical, or energy-harvesting functions. The prediction of film-substrate deformation instabilities is of importance, but the phenomenon is inherently complex and difficult to simulate using common analytical/numerical tools. In this presentation, we highlight our recent developments of a practical computational technique utilizing the embedded imperfections to trigger wrinkle formation. This approach leads to direct modeling from pre-instability to post-instability, including transitions of the instability modes, in a seamless manner, and gives new insights into the evolution of wrinkle patterns. The investigations feature large-scale 3D simulations under general in-plane compression, spanning the entire biaxial spectrum in between the extreme cases of uniaxial and equi-biaxial loading. The loading-unloading histories can also be directly analyzed. The state of biaxiality is found to influence the surface pattern significantly, and each instability mode can be traced back to certain abrupt changes in the overall load-displacement response.

Dr. Nabila A. Karim
Fuel Cell Institute
Universiti Kebangsaan Malaysia, Malaysia

Title of Invited Talk

Overview of the research progress and challenges of the application of carbon-based materials in Enzymatic Biofuel Cell (EBFC)

Abstract of Invited Talk

EBFC as micro-power sources successfully supplied power for the biosensor in the military and environmental application and implantable medical devices because it has advantages such as good bio-compatibility, easy miniaturization, and mild working conditions. The enzyme used as bio-catalyst shows high selectivity and specificity in the fuel oxidation, eliminating the membrane separator for easy EBFC miniaturization. The activity density obtained from the total enzyme loading on the electrode surface per unit area conducts the reaction in EBFC. Loading can be optimized using support materials that highly interact with the enzymes. Support materials require a high surface area to improve the electrochemical performance of the enzyme in EBFC. Support requires must show low aggregation for enzyme immobilization, good electrocatalytic activity, and electronic properties. Various supports have been used in EBFC; however, carbon-based supports have been widely applied in EBFC because they have various advantages. Among the carbon-based supports that have been developed in EBFC are single-wall and multi-wall carbon nanotubes, carbon nanoparticles, carbon black, mesoporous carbon, graphene, carbon spheres, and multiples carbon supports. All these types of carbon are commonly used in renewable energy conversion, alternative energies, and storage systems, and some carbon-based materials may have high potential that has not been applied in EBFC. This paper presented current research using carbon-based materials and challenges to produce high performance in applications in EBFC.

Assoc. Prof. Dr. Huy-Tuan Pham
Faculty of Mechanical Engineering
Ho Chi Minh City University of Technology and Education, Vietnam .

Title of Invited Talk

Design and Optimization of High-Precision Compliant Mechanisms for Vibration-Assited Machining Methods

Abstract of Invited Talk

Ultrasonics and vibration-assisted machining are hybrid machining methods that combine small vibration with high or moderate frequency, respectively, into either the subtractive or additive machining approaches to enhance performance and efficiency. The integration of oscillation to the cutters or workpieces to vibrate them in one or more directions intermittently reduces the contact area between the blade and the workpiece. Recent researches show that the benefits of these advanced machining methods are the reduction in friction, machining force, cutting heat, reduction of tool wear, and extension of tool life. Therefore they improve the surface finish and quality, enhance chips removal, and suppression of burr formation. However, the challenges of establishing this manufacturing equipment are the vibration transferring from ultra-high precision actuators to the machining stages without damaging them. The compliant mechanism is a favorable solution for high-precision machines due to its spectacular advantages. This paper proposes a new 2-DOF XY vibration compliant stage using flexural hinges and leaf springs for a vibration-assisted milling application. The design uses a symmetrical two-stage lever mechanism to transfer and amplify vibrations from piezo-actuators. In the design process, the Taguchi method and finite element analysis are used to evaluate the influence of each design variable on the design optimization problem. The objectives of the design are to maximize the first-order natural frequency and minimize the parasitic motion while maintaining the equivalent stress under the allowable limit. Optimum designs are found which would be preferable for various vibration-assisted milling applications.

Assoc. Prof. Ir. Dr. Wong Yew Hoong
Department of Mechanical Engineering,
Faculty of Engineering, University of Malaya, Malaysia

Title of Invited Talk

Study of Trigonal-Sm₂O₃ as High-k Gate Dielectric on Ge-Based Metal-Oxide-Semiconductor (MOS) Device Structure

Abstract of Invited Talk

In this study, Sm₂O₃/Ge stack based capacitor prepared from thermally oxidized/nitrided sputtered metallic Sm on Ge semiconductor in N2O ambient have been comprehensively inv, , estigated. The film crystall, inity, chemical, , composition and interface chemical bonding states stability was characterized from X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Formation of trigonal-Sm₂O₃ dielectric interface together with an interfacial layer containing asymmetrically distributed (Ge-O, Sm-O-Ge and Ge-N) species has been verified. Suppression of GeO (g) volatilization was evident from the XPS analysis due to germanate (Sm-O-Ge) formation. Structural morphology characterization using high resolution transmission electron microscope (HRTEM) also validated double stack amorphous interfaces obtaining physical oxide thickness (tox) from 4.25 - 6.91 nm. Band alignment and electrical measurements revealed the highest conduction band offset (CBO), ∆Ec of 2.60 eV and valence band offset (VBO) ∆Ev of 2.98 eV leading to lowest leakage current density Jg ~ 8.38 ∙ 10-6 A cm-2 at enhanced breakdown field, E_BD of 13.31 MV cm-1. The large breakdown field has been ascribed to fewest effective oxide charge (Q_eff), slow trap density, (Q_it) and interface traps density (D_it) at this duration. Additionally, a low equivalent oxide thickness, t_EOT ~ 0.75 nm with a high dielectric constant k ~ 31.19 was achieved but with high D_it ~ 1013 eV-1cm-2. These properties render that Sm2O3 could serve as dielectric material for future high-k/Ge stack based metal oxide semiconductor technology, although requires further investigation for D_it improvement.

Prof. Mohd Hafiz Dzarfan Othman

Advanced Membrane Technology Research Centre (AMTEC)
University Teknologi Malaysia, Malaysia

Title of Invited Talk

Fabrication of Inexpensive Ceramic Membranes via Phase Inversion/Sintering Process and Their Application in Water & Wastewater Treatment

Abstract of Invited Talk

Membrane technology has been widely embraced in water and wastewater treatments due to high efficiency and excellent product output, which ensures the consistent delivery of clean and safe water to meet the ever-increasing global water demand. Polymeric membranes have been the most commonly used materials in membrane applications attributed to low material cost and high market availability. Since the last two decades, ceramic membranes have gradually emerged as an excellent alternative to polymeric membranes as these membranes exhibit excellent chemical and thermal resistance, superior mechanical properties, and longer operational lifetime, which could not be achieved by some conventional polymeric membranes. However, ceramic membranes suffer from high material costs that hinder their uses in real applications. Recently, our research group have successfully developed various types of low-cost high-performance ceramic membranes from alternative ceramic materials, such as natural occurring clays, agricultural and industrial waste, and animal bones via phase inversion/sintering process. These membranes have shown some impressive performance in several membrane applications, such as microfiltration, photocatalytic membrane, and membrane distillation. With these successful breakthroughs, ceramic membranes have been made to be more affordable and economically feasible for real membrane applications with enhanced performance efficiency.

Symposium Proceedings 2021 (PDF DOWNLOAD)