An On‐Skin‐Formed Silk Protein Bioelectrode for Conformable and Robust Electrophysiological Interface

The electrophysiological interface is essential for understanding electrical activities within biological organisms and human‐machine interaction. However, traditional preformed bioelectrodes show insufficient interface contact with hairy and irregular skin, causing signal attenuation and distortion. Here, an on‐skin‐formed silk protein bioelectrode is reported with a conformable and robust interface, achieving a high signal‐to‐noise ratio for electromyographic signals, showing up to a 38.9% increase compared to traditional ones. The fluid‐gel transition of silk protein is induced by a gelling agent composed of ethanol and sodium alginate, leading to a conformable and seamless interface with hairy and irregular human skin, thus resulting in a high signal‐to‐noise ratio. The developed bioelectrode can record electrophysiological signals stably, even underwater. Additionally, human‐machine interaction using electromyographic signals is designed to precisely control the model car's motion trajectory. This work presents an effective method for developing a seamless and conformable electrophysiological interface in bioelectronics. An on‐skin‐formed silk protein bioelectrode is developed from the fluid‐gel transition of silk protein induced by a gelling agent composed of ethanol and sodium alginate, which achieves a conformable and robust interface with hairy and irregular human skin. The resulting bioelectrode is used to enable a human‐machine interaction for precise control of the model car's motion trajectory.