Soft-Actuated Cuff Electrodes with Minimal Contact for Bidirectional Peripheral Interfaces

Neural interfaces with embedded electrical functions, such as cuff electrodes, are essential for monitoring and stimulating peripheral nerves. Still, several challenges remain with cuff electrodes because sutured devices can damage the nerve by high pressure and the secured contact of electrodes with the nerve is hard to accomplish, which however is essential in maintaining electrical performance. Here, a sutureless soft-actuated cuff electrodes (SACE) that can envelop the nerve conveniently by creating a bent shape controlled upon fluid injection, is introduced. Moreover, fluid injection protrudes part of the device where electrodes are formed, thereby achieving minimized, soft but secure contact between the electrodes and the nerve. In vivo results demonstrate the successful recording and stimulation of peripheral nerves over time up to 6 weeks. While securing contact with the nerve, the implanted electrodes can preserve the nerve intact with no reduction in blood flow, thereby indicating only minimal compressive force applied to the nerve. The SACE is expected to be a promising tool for recording and stimulation of peripheral nerves toward bidirectional neuroprostheses.