Integrated sensing for ionic polymer–metal composite actuators using PVDF thin films

Abstract Compact sensing methods are desirable for ionic polymer–metal composite (IPMC) actuators in microrobotic and biomedical applications. In this paper a novel sensing scheme for IPMC actuators is proposed by bonding an IPMC and a PVDF (polyvinylidene fluoride) thin film with an insulating layer in between. The insulating layer thickness is properly designed to minimize the stiffness of the composite IPMC/PVDF structure while reducing the electrical feedthrough coupling between the IPMC and PVDF. A distributed circuit model is developed to effectively represent the electrical coupling dynamics, which is then used in real-time compensation for extraction of the true sensing signal. Experimental results show that the developed IPMC/PVDF structure, together with the compensation algorithm, can perform effective, simultaneous actuation and sensing. As the first application, this sensori-actuator has been successfully used for performing and monitoring open-loop micro-injection of living Drosophila embryos.