Prof. Lei Zuo

• Energy Harvesting: From Wireless Sensors to Blue Energy

    Abstract: Energy harvesting has attracted huge research attention in the past two decades. For the academic papers alone, the number of energy harvesting papers published a year increased from about 100 to over 1000 from 2007 to 2017. By converting the environmental energy into electricity, the energy harvesting provides a promising solution to power wireless sensors at mW level without costly wiring or battery replacement. Energy harvesting has also extended to watt level to power portable electronics, like harvesting from human motions. More recently, researchers also investigated the energy harvesting from vehicles and civil structures, at 100W to 100KW for self-powered vibration control. Very active research has been going on worldwide on blue energy, to harvest vast amount power from ocean wave oscillations. In this talk, we will review the energy harvesting at various energy scales from history perspective, and examine the challenges in the multiple disciplines of vibration, dynamics, electronics, control, material science and mechatronics design for energy harvesting. The future research directions and commercialization opportunities are also discussed.

• Bio Sketch

    Lei Zuo completed his PhD in Mechanical Engineering from MIT in 2004 and BS with highest honor from Tsinghua University in 1997. He also holds two MS degrees in both Mechanical and Electrical Engineering from MIT. After working on industry for four years, he joined in State University of New York at Stony Brook in 2008 as an assistant professor and was promoted to associate professor in 2013. He moved to Virginia Tech in 2014 and was promoted to full professor rank in 2017. He currently serves the Director of National Science Foundation (NSF) Industry-University Collaborative Research Center (IUCRC) for Energy Harvesting Materials and System.

    Lei Zuo research interests include energy harvesting, mechatronics design, vibration control, clean energy manufacturing, marine and hydrokinetic energy, and thermoelectricity. Since 2008 he has secured almost 12 million US dollars of research funding (nearly $10M as the PI) from various federal and state funding agencies as well as industry. Zuo has published over 230 papers in journals and conferences, including 5 with best paper and 2 with best student paper awards. The American Society of Mechanical Engineers (ASME) recognized him as “a pioneering researcher in energy harvesting, especially at larger energy scale” with its 2015 Thar Energy Design Award. He was named as an ASME Fellow in 2016. Zuo is also the sole recipient of the 2017 ASME Leonardo Da Vinci Award/Medal, for his “eminent achievement in the design or invention of a product which is universally recognized as an important advance in machine design”. He also won R&D Awards twice (2015 and 2011) from R&D Magazine, which recognizes the top 100 technology innovations in the word of the year. He currently serves as a technical editor for IEEE/ASME Transactions on Mechatronics and associate editor for ASME Journal of Vibration and Acoustics and IFAC journal Mechatronics.

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Prof. Wei-Hsin Liao

• Energy Harvesting from Vibration and Human Motion

    Abstract:Most of the ambient energy, which was regarded useless in the past, now is under the spotlight. With the rapid developments on low power electronics, future personal mobile devices and remote sensing systems might become self-powered by scavenging energy from their surroundings. Kinetic energy is one of the promising energy forms in our living environment, e.g., human motion and vibration. We have proposed an energy flow to clarify the functions of piezoelectric energy harvesting, dissipation, and their effects on the structural damping of vibrating structures. Impedance modeling and analysis were performed. We have designed an improved self-powered switching interface for piezoelectric energy harvesting circuits. With electromagnetic transduction, we also proposed a knee-mounted energy harvester that could convert the mechanical power from knee joints into electricity during walking. On the other hand, we have developed magnetorheological (MR) fluid devices with multiple functions, including linear dampers and rotary actuators. Novel self-sensing MR dampers with power generation, which integrate the dynamic sensing, MR damping and power generation functions, were proposed and investigated. In addition, multifunctional rotary actuator was also designed to integrate motor/generator part and MR fluids into a single device. The actuator could function as motor, generator, clutch and brake, with compact size and less power consumption. The developed actuators were promising for various applications. In this talk, related research and key results will be presented.

• Biography

    Wei-Hsin Liao received his Ph.D. in Mechanical Engineering from The Pennsylvania State University, University Park, USA. Since August 1997, Dr. Liao has been with The Chinese University of Hong Kong, where he is now Chairman and Professor of Mechanical and Automation Engineering. His research interests include smart structures, vibration control, energy harvesting, mechatronics, and medical devices. His research has led to publications of over 220 technical papers in international journals and conference proceedings, 16 patents in US, China, Hong Kong, Taiwan, Japan, and Korea. He was the Conference Chair for the 20th International Conference on Adaptive Structures and Technologies in 2009; the Active and Passive Smart Structures and Integrated Systems, SPIE Smart Structures/NDE in 2014 and 2015. He is a recipient of the T A Stewart-Dyer/F H Trevithick Prize 2005, the ASME 2008 Best Paper Award in Structures, the ASME 2017 Best Paper Award in Mechanics and Material Systems, and three Best Paper Awards in the IEEE conferences. At CUHK, he received the Research Excellence Award (2011), and was awarded Outstanding Fellow of the Faculty of Engineering (2014). He received the SPIE 2018 SSM Lifetime Achievement Award. Dr. Liao currently serves as an Associate Editor for Mechatronics, Journal of Intelligent Material Systems and Structures, as well as Smart Materials and Structures. He is a Fellow of the American Society of Mechanical Engineers, Institute of Physics, and The Hong Kong Institution of Engineers.

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Prof. Yuji Suzuki

• Print-circuit-boad-enhanced Electret Rotational Energy Harvester for Wearable Devices

    Abstract: Energy harvesting from human walking is suitable for powering battery-less wearable devices. In such applications, rotational energy harvesters (EHs) have advantages over vibration EHs due to the fact that low-frequency 3-D vibration with 3-axis rotation is dominant for human motion. Among various transduction mechanisms, electret generators are advantageous in terms of higher output power at low frequencies and their low-profile structures. A novel low-profile rotational electret energy harvester (EH) is prototyped for capturing power from low-frequency vibration. CYTOP EGG is employed to realize high surface potential over 800 V. Thanks to cost-effective flexible print circuit boards (PCB), except the center part for the ball bearing housing, the thickness of the rotational part is only 2.8 mm, which is at least less than half of the previous rotational EHs. Output power up to 200 µW has been obtained at a low rotational speed of 1 rps. In addition, a dynamic model of arm-equipped rotational energy harvester (EH) during human walking is proposed toward development of standard testing methods for such energy harvesters. The model describes realistic arm swing based on a two link with shoulder and elbow joints rotation, and includes the electro-mechanical coupling with a rotational electret EH. It is found that simulated output power is in accordance with our experimental data using a multi-link robot. Effects of different design parameters on the output power are also examined with the present model under different walking conditions.

• Bio Sketch

    Yuji Suzuki received the B.S., M.S., and Dr.Eng. degrees in mechanical engineering from the University of Tokyo, Tokyo, Japan, in 1987, 1989, and 1993, respectively. He is currently with the Department of Mechanical Engineering, University of Tokyo, as a Professor. He serves as Steering Committee Member of PowerMEMS Conference, Organizing Committee member of IEEE International Symposium on Electret. He also served as the general co-chair of IEEE MEMS2010 (Hong Kong) and the general chair of PowerMEMS 2017 (Kanazawa). His research interests include MEMS-based energy harvesting using electrets, micro energy conversion such as microscale combustion, and optimal design/control of micro heat and fluid flow.