Wirelessly Powered Soft Magnetic Robot with Microneedle for Electrical Stimulation and Drug Delivery

Electrical stimulation and microneedle-mediated drug delivery emerge as promising therapies in gastrointestinal (GI) motility disorders and inflammatory conditions. However, on-demand intervention therapy in enclosed narrow GI remains a challenge. Herein, a magnetic-driven soft membrane robot is presented that synergistically combines microneedle-mediated electrical stimulation and drug delivery. The membrane robot's bipolar magnetization enables switching between two surfaces by external magnetic fields, where N-pole drives treatment surface with microneedle to penetrate GI wall and S-pole initiates smooth surface for low resistance locomotion. The membrane robot utilizes magnetically coupled resonant wireless transmission to enable regulated electrical stimulation with 86.7% efficiency at 6 cm distance, while providing tunable voltage (0–20 V) and programmable pulse waveforms (0.4–50 ms width) for adaptive bioelectrical modulation. The drug-loaded microneedle array serves dual roles as both a penetrating electrode and a therapeutic interface, delivering electrical stimulation while simultaneously releasing encapsulated agents upon tissue penetration. In vitro experiments of the multimode motion and multifunctional treatment are validated in a fresh pig gut. This integrated membrane magnetic robot offers great potential in GI diagnostics, personalized neuromodulation, and on-demand drug release applications.