Int. J. Materials and Product Technology, Vol. X, No. Y, xxxx 1 Copyright © 200x Inderscience Enterprises Ltd. A novel 2-DOF haptic master device using bi-directional magneto-rheological brakes: modelling and experimental investigation Phuong-Bac Nguyen, Jong-Seok Oh and Seung-Bok Choi* Smart Structures and Systems Laboratory, Department of Mechanical Engineering, Inha University, Incheon 402-751, Korea Fax: +82-32-8681716 E-mail: nguyenphuongbac@gmail.com E-mail: ojshero@gmail.com E-mail: seungbok@inha.ac.kr *Corresponding author Abstract: In this study, configuration and modelling of haptic master device for minimally invasive surgery (MIS) using bi-directional magneto-rheological (BMR) brakes are proposed. This haptic device consists of two bi-directional magneto-rheological (BMR) brakes incorporated with a gimbal mechanism for realising a 2-DOF rotational motion. The total torque induced from the BMR brakes of the haptic device is computed based on Bingham model. A prototype for the design is then manufactured and several experiments on this prototype are undertaken to investigate the ability of compensating the undesired torque as well as sensing in hard and soft environments. Keywords: haptic master device; MR fluid; minimally invasive surgery; MIS; bi-directional MR; BMR; brake. Reference to this paper should be made as follows: Nguyen, P-B., Oh, J-S. and Choi, S-B. (xxxx) ‘A novel 2-DOF haptic master device using bi-directional magneto-rheological brakes: modelling and experimental investigation’, Int. J. Materials and Product Technology, Vol. X, No. Y, pp.000–000. Biographical notes: Phuong-Bac Nguyen received his BEng and MEng degrees in Mechanical Engineering from Ho Chi Minh City Polytechnic University, Vietnam, in 2000 and 2007, respectively. He is currently pursuing his PhD degree in the Department of Mechanical Engineering, Inha University, South Korea. His research interests include modelling and control of hysteresis, haptics, MR/ER and piezoceramic applications. Jong-Seok Oh is a doctorate student of Mechanical Engineering at Inha University. He is conducting research in the area of medical robot system with haptic master. Seung-Bok Choi received his BSc in Mechanical Engineering from Inha University, Korea, in 1979 and MSc and PhD degrees from Michigan State University, East Lansing, in 1986 and 1990, respectively. He is currently a Fellow Professor of Mechanical Engineering at Inha University. His research interests include smart materials and structures, suspension systems, robotic systems, and advanced control theories. He has published more than 300 international journal papers.