Precision position control of ionic polymer metal composite

The ionic polymer metal composite (IPMC) is a novel smart polymer material. It shows significant potential in the application for low-mass high-displacement actuators. The IPMC behavior in open loop is not repeatable and also it is difficult to maintain its tip displacement constant at a specified position in open loop. Hence closed-loop control of IPMC is important. In this paper model-based precision position control of an IPMC strip in a cantilever configuration is demonstrated. After implementing the closed-loop position control the overshoot decreased to 20% from 205.34% in open loop, and the settling time reduced to 1 s from 27 s in open loop. Precision micro-scale position-control capability of the IPMC was also demonstrated. A 20-mum position resolution was achieved with a position noise of 7.6-mum rms.