A Wirelessly Tunable Electrical Stimulator for Ionic Electroactive Polymers

Ionic electroactive polymers (iEAPs) respond to electrical stimulation by changing in shape, caused by ion displacement inside the polymer. Due to similarities between the mechanism of action of iEAPs and the physiology of native muscle tissue, iEAPs have great potentials in applications requiring skeletal muscle regeneration. This paper presents a new system-level solution for the realization of a tunable electrical stimulator for iEAPs, capable of remotely altering the degree and the direction of the movement of iEAPs. Without using digital modulation schemes, the proposed stimulator uses frequency at the primary side, to wirelessly tune the magnitude and the polarity of the electric field generated at the secondary side, enabling remote stimulation of iEAPs. As a proof of concept, the proposed stimulator is implemented using custom-off-the-shelf components. The performance of the stimulator is extensively evaluated under various conditions, including coil misalignment. The stimulator is also integrated with iEAP samples, and the functionality of the end-to-end module is examined based on the response and the movement characteristics of iEAPs in a series of in vitro experiments. Results demonstrate the feasibility of using the proposed system as a reliable electrical stimulator for iEAPs.