Highly stretchable electrochromic hydrogels for use in wearable electronic devices

Abstract

Even though several stretchable electrochromic (EC) materials have been reported, effective and facile strategies for the development of ideal intrinsically stretchable EC materials with various colors, simple preparation, low energy consumption, excellent performance, and practicability are still urgently required. Herein, an ideal inherently stretchable EC device is demonstrated and constructed by combining a novel intrinsically stretchable EC material as well as new asymmetric stretchable conductive electrodes where Ag nanowires are used as the cathode and Au nanosheets are used as the anode in order to balance the conductivity, transmittance, stability, and mechanical properties. A stretchable EC material containing a highly transparent, elastic, and conductive polyacrylamide (PAAM) hydrogel and some new water-soluble EC molecules exhibits easily selectable multicolor-tunable property, desirable coloration efficiency with low energy consumption, and health- and environment-friendly characteristics. Further, color changes in the device can be easily and reversibly manipulated in seconds from yellow to red or brown under tensile strain. These promising results reveal that this new method/process is easily applicable and has promising potential for future wearable electronic displays.