Skin-Attachable Piezoelectric Patch Sensors for Self-Driven Rehabilitation of Stroke Patients by Simple Game.

Rehabilitation is crucial for stroke survivors to restore motor functions and improve the quality of life. However, existing rehabilitation systems are relatively large and require professional assistance, which limits their accessibility. This study develops small patch-type sensors using biocompatible and flexible single-crystalline piezoelectric thin films to monitor the accuracy and response time of finger, hand, and forearm movements. The sensors attached to the skin of joints and muscles exhibit distinct output voltages in response to the directions and degrees of movement, with high sensitivity, fast response times, exceptional stability, and biocompatibility. Furthermore, the sensors on the forearm can detect subtle skin deformations associated with muscle contraction and relaxation movements of the radial, median, and ulnar nerves when performing different hand gestures used in the rock-paper-scissors game, resulting in discernible voltage output patterns. We develop a self-driven rehabilitation system that plays the rock-paper-scissors game, where the generated voltage signals from skin-attachable sensors determine whether the game is won or lost within a specific response time. This approach offers potential accessible and efficient rehabilitation, improving patient outcomes through self-motivated healthcare and entertainment.