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

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.