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 anti-drying, 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 one-dimensional (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.