Skin-integrated, biocompatible, and stretchable silicon microneedle electrode for long-term EMG monitoring in motion scenario

Electromyography (EMG) signal is the electrical potential generated by contracting muscle cells. Long-term and accurate EMG monitoring is desirable for neuromuscular function assessment in clinical and the human-computer interfaces. Herein, we report a skin-integrated, biocompatible, and stretchable silicon microneedle electrode (SSME) inspired by the plant thorns. The silicon microneedles are half encapsulated by the polyimide (PI) to enhance the adaptability to deformation and resistance to fatigue. Thorn-like SSME is realized by the semi-additive method with a stretchability of not less than 36%. The biocompatibility of SSME has been verified using cytotoxicity tests. EMG monitoring in motion and long-term has been conducted to demonstrate the feasibility and performance of the SSME, which is compared with a commercial wet electrode. Hopefully, the strategies reported here can lead to accurate and long-term EMG monitoring, facilitating an effective and reliable human-computer interface.