Flexible battery-type pressure sensor enhanced with locked water by calcium ion in graphene oxide solid electrolyte

Wearable pressure sensors have received recent attention due to their contributions to artificial intelligence, electronic skin, and the Internet of Things. However, this traditional sensor is faced with the integration dilemma caused by the need for external energy supply devices. Targeting this obstacle, here, we report a scheme that improves the battery as a pressure sensor. Benefiting by the redox potential conversion mechanism and the water-retention characteristics of calcium ion, this scheme can encode pressure signals into electrical signals, thus converting the battery into a pressure sensor. Proposed battery-type sensors exhibit notable sensing performance and have a high total power density of 1.93 mW cm−2 due to the improvement of conductivity to 1.08 × 10−3 S/cm, which is ∼4,000 times higher than that of the sensor prepared by unmodified GO solid electrolyte. Therefore, this study provides a general platform for manufacturing high-performance one-body electronic skin in passive mode.