Anti-drying, transparent, ion-conducting, and tough organohydrogels for wearable multifunctional human-machine interfaces

There is increasing interest in the "Internet of Things" (IoT) and the development of wearable intelligent devices with human-machine interfaces (HMIs). Flexible touch panels have received wide attention because they are intuitive HMIs. However, most existing flexible touch panels can only detect a single touch or rely on massive electrodes and complex sensor arrays for multi-touch detection. Herein, a long service life (>5 months), wearable, and Multifunctional HMI (MHMI) with only two electrodes is reported for various applications. An antidrying, transparent, ion-conducting, and tough organohydrogel with satisfactory stretchability (>450%) and long life is developed as a sensing material. A parallel mutual inspection detection structure based on ion conductors is designed to detect single or multiple touches accurately and sensitively. This structure comprises a pair of organohydrogel strips in a horizontal or spiral form embedded in a flexible substrate to construct onedimensional (1D) or two-dimensional (2D) MHMIs. The 1D- and 2D-MHMIs can be used as linear controllers and 2D movement controllers, respectively. The multi-touch recognition function endows the MHMIs with greater operability by programmatically implementing multi-device switching and multi-function selection in a versatile and effective manner. Therefore, the devices have great potential for use in the IoT-related applications.