Ionic polymer–metal composites (IPMCs) have been considered for various applications due
to their light weight, large bending, and low actuation voltage requirements. However, their
response can be slow and vary widely, depending on various factors such as fabrication
processes, water content, and contact conditions with the electrodes. In order
to utilize their capability in various high-performance microelectromechanical
systems, controllers need to address this uncertainty and non-repeatability while
improving the response speed. In this work, we identified an empirical model
for the dynamic relationship between the applied voltage and the IPMC beam
deflection, which includes the uncertainties and variations of the response. Then,
four types of controller were designed, and their performances were compared: a
proportional–integral–derivative (PID) controller with optimized gains using a
co-evolutionary algorithm, and three types of robust controller based on , with loop shaping, and μ-synthesis, respectively. Our results show that the robust control techniques can
significantly improve the IPMC performance against non-repeatability or parametric
uncertainties, in terms of the faster response and lower overshoot than the PID control,
using lower actuation voltage.