A highly sensitive hydrogel panel with touch-enhanced sensing property for handwriting performance

Hydrogel sensors for flexible touch-sensing devices have sparked tremendous research interest in wearable electronics for broad applications such as artificial intelligence, information secrecy, and interactive control devices. Although many achievements have been reached in the hydrogel touch-sensing devices, profound challenges remain in the establish of new sensing system and the improvement on the sensitivity to ensure smooth and sensitive touching experience. Herein, a flexible hydrogel sensor as the touchable panel was developed and showed excellent tough-sensing performance for handwriting with high sensitivity. With the flexible and tough hydrogel as the contact layers, the sandwiched hydrogel panel was prepared and showed good touch-sensing performance with high sensitivity (∼500 % ΔI/I 0 , 12.65 N −1 ). This improvement on the sensitivity was ascribed to the increasement of current during the touching process originated from the formation of new circuit branch. Furthermore, it could be used as a portable touchpad for the wearable handwriting. This hydrogel sensor with the high sensitivity for handwriting has great potential in the fields of intelligent screen and wearable electronic device.