Untethered thin-film neurostimulator wrapped around tiny nerve trunks for wireless neuromodulation.

Electrical stimulation of tiny peripheral nerve trunks for near-organ neuromodulation enables precise electroceutical therapy for refractory diseases, but long-term stable neuromodulation of these delicate, fragile nerve trunks remains an engineering challenge. Here, we report the development of NeuroWrap Ultrasonic Stimulator (NWUS), an untethered, self-adhesive thin-film neurostimulator capable of conformally wrapping around tiny nerve trunks. The untethered architecture can help avoid the damage or rupture of tiny nerves due to uncontrollable micromotion of lead wires during bodily movements. The NWUS is an ultrasound-responsive acoustoelectric converter with optimized impedance matching, which enables highly effective wireless electrical stimulation. The electroceutical application of NWUS was further illustrated in chronic vagus nerve stimulation for immunomodulation therapy in a rat model. The wireless neuromodulation therapy of rat experimental autoimmune myocarditis was proven to restore left ventricular function, suppress proinflammatory cytokine expression as well as macrophage infiltration within cardiac tissue, and promote regulatory T cell recruitment along with increased anti-inflammatory cytokine levels.