A fish robot driven by piezoceramic actuators and a miniaturized power supply

In this paper, we have introduced a prototype of a fish robot driven by unimorph piezoceramic actuators. To improve the swimming performance of the fish robot in terms of tail-beat angle, swimming speed, and thrust force, we used four light-weight piezo-composite actuators (LIPCAs) instead of the two LIPCAs used in the previous model. We also developed a new actuation mechanism consisting of links and gears. Performance tests of the fish robot were conducted in water at various tail-beat frequencies to measure the tail-beat angle, swimming speed, and thrust force. The tail-beat angle was significantly better than that of the previous model. The best tail-beat frequency of the fish robot was 1.4 Hz and the maximum thrust force was 0.0048 N. A miniaturized power supply, which was developed to excite the LIPCAs, was installed inside the fish robot body for free swimming. The maximum free-swimming speed was 3.2 cm/s. Recommended by Editorial Board member Hyoukryeol Choi under the direction of Editor Jae-Bok Song. This work was supported by the Korea Research Foundation under grant KRF-2004-005-D00045. Quang Sang Nguyen received the BS (2001) and MS (2006) from Hochiminh City University of Technology, Vietnam. Formerly an assistant lecturer of Naval Architect and Marine Engineering, Hochiminh City University of Technology, Vietnam (2001-2006), he is currently a Ph.D. student at the Department of Advanced Technology Fusion, Konkuk University. His specialty is biomimetic system design and smart material application. Seok Heo received the B.S., M.S. and Ph.D. degrees in Mechanical Engineering from Dongguk University in 1998, 2000, and 2003, Respectively. Currently he is a Research Professor at the Artificial Muscle Researcch Center, Konkuk University, Seoul, Korea. His research interests include biomimetics, vibration analysis, system design and control, and smart materials and structures. Hoon Cheol Park received the B.S. (1985) and M.S. (1987) from Seoul National University in Seoul, Korea and Ph.D. (1994) from the University of Maryland at College Park, MD, USA. He joined the Department of Aerospace Engineering, Konkuk University in Seoul, Korea, in 1995, and he is currently a Professor in the Department of Advanced Technology Fusion. His professional experience includes Kia Motors (1986–1988) and Korea Aerospace Research Institute (1994–1995). His specialty is finite element analysis and his recent research has focused on biomimetics. Nam Seo Goo graduated with honors in 1990 from the Department of Aeronautics Engineering of Seoul National University, and he got a masters degree and Ph.D. from the Department of Aerospace Engineering at the same university in 1992 and 1996, respectively. His Ph.D. thesis was on the structural dynamics of aerospace systems. As soon as he obtained the Ph.D. he entered the Agency for Defense development as a senior researcher. In 2002, after four years of service, he joined the Department of Aerospace Engineering at Konkuk University, Seoul, Korea, where he is currently serving as an Associate Professor of the Department of Advanced Technology Fusion. His current research interests include structural dynamics of small systems, smart structures and materials, and MEMS applications. Taesam Kang is a Professor of the Department of Aerospace and Information System Engineering, Konkuk University. He received the B.S., M.S. and Ph.D. degrees from Seoul National University in 1986, 1988 and 1992, respectively. His current research areas are robust control theories and the application of those theories with regard to flight control, development of micro-aerial vehicles and fish robots. Kwang Joon Yoon was awarded the BS (1981) and M.S. (1983) in Aeronautics Engineering from Seoul National University and Ph.D. (1990) in Aeronautics and Astronautics Engineering from Purdue. Since 1991 he has been a Professor at Konkuk University in Korea, where he is currently a Professor of Aerospace Engineering, the Director of the National Research Laboratory for Active Structures and Materials, the Director of the Artificial Muscle Research Center, and the Director of the Smart Robot Center. His current research interests include smart structures and materials, micro-aerial vehicles, and insect-mimetic micro-robot systems. Seung Sik Lee received the B.S. (1996) and M.S. (1998) in Civil Engineering from Hongik University in Seoul, Korea and Ph.D. (2003) in Civil Engineering from Georgia Institute of Technology, GA, USA. Currently he is a Senior Researcher at Korea Institute of Marine Science & Technology Promotion.