Title: Robot assisted facial expressions with segmented shape memory alloy actuators

Authors: Dushyantha Jayatilake; Kenji Suzuki

Addresses: Graduate School of Systems and Information Engineering, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8573, Japan. ' Center for Cybernics Research, University of Tsukuba/JST, 1-1-1 Tennodai, Tsukuba 305-8573, Japan

Abstract: This paper introduces a robotic technology-based supporting device, the robot mask, to enhance facial expressiveness and support physiotherapy for facial paralysed persons. The wearable device, which consists of shape memory alloy (SMA)-based linear actuators, functions by pulling the facial skin towards anatomically selected directions. Since facial expressions are silent, SMA was selected over electrical motors. This paper introduces a compact and fully controllable actuation unit with position feedback and a novel controlling scenario that uses the selected hybrid actuation of bidirectional multi segment SMA wires in series to pull the wires. When designing the actuators, a biomechanical analysis was conducted to find anatomical parameters of natural smiles, and the robot mask was evaluated for its suitability as a facial expression supporter.

Keywords: shape memory alloys; SMA actuators; facial paralysis; facial expressiveness; silent actuation; SIAC; segmented hybrid control; neurorobotics; facial expressions; robot masks; physiotherapy; wearable devices; position feedback; biomechanical analysis; biomechanics; anatomical parameters; natural smiles; robots.

DOI: 10.1504/IJMA.2011.045254

International Journal of Mechatronics and Automation, 2011 Vol.1 No.3/4, pp.224 - 235

Available online: 01 Feb 2012 *

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