An IPMC actuated robotic surgery end effector with embedded force sensing

Abstract

The recent growth of patient acceptance and demand for robotic aided surgery has stimulated the progress of research where in many applications the performance has been proven to surpass human surgeons. An inherently force compliant and back-drivable properties of polymers, Ionic Polymer-metal Composite (IPMC) in this case, has shown its potential to undertake precise surgical procedures in delicate environments of medical practice. This is because IPMCs have similar actuation characteristics to real biological systems ensuring the safety of the practice. Nevertheless, little has been done in developing IPMCs as a rotary joint actuators used as functional surgical devices. This research proposes and demonstrates the design of a single degree of freedom (1DOF) robotic surgical instrument with one skeleton-joint mechanism actuated by IPMC with an embedded strain gauge as a feedback unit, and controlled by a gain-schedule PI controller. With the simplicity of the system it was proven to be able to cut to the desired controlled force (up to 8 gf cutting force) and hence depth.