Design and Development of a Force Feedback System for a SMA Based Gripper as a Minimally Invasive Surgical Tool

This work introduces a novel method of integrating a force feedback system for a gripper actuated by a Shape Memory Alloy (SMA) spring actuator which is actuated by external heating. The targeted application of this gripper mechanism is to be used in a Minimally Invasive Surgical (MIS) tool since there is a need of miniaturization and enhancement of feedback to the surgeon. The SMA actuator and a test apparatus containing the gripper which is activated by hot and cold fluid sources was developed in this study. The actuator is operated by controlling the fluid temperature and flow rate through a customized multi-functional controller. The controller operates the opening and closing motion while maintaining the gripper force by controlling the flow rate of the fluid sources. The gripper force sensing was achieved through a strain gauge based sensing method. Finally, the force controlling performance of the system was evaluated.