Stretchable electrochromic devices enabled via shape memory alloy composites (SMAC) for dynamic camouflage

Abstract

Electrochromic device is a kind of device that can produce color change under the actuation of electric signal. It has attracted wide attention because of its dynamic color change properties, color diversity and convenience of driving signals. These properties highlight its potential application prospects in dynamic display, anti-counterfeiting treatment, biomedicine and other fields. In this study, stretchable photonic crystals are prepared by nano-imprint technology, soft actuators made by shape memory alloy composites (SMAC) were developed based on shape memory alloy (SMA). A stretchable electrochromic device is obtained by integrating the stretchable photonic crystal and SMAC. The electrochromic properties of the device is tested under different voltages. It is found that under the voltage of 1.0 V–1.5 V, it can achieve color changing in entire visible light range, and the total deformation required is less than 30%. The properties of stretchable electrochromic devices based on SMAC is comparative analyzed with that of other electrochromic devices or structures. The results show that the proposed stretchable electrochromic device has the characteristics of low driving voltage, good compliance, wide color changing range, short response time and large effective color changing area. Finally, the excellent soft dynamic display and camouflage functions of stretchable electrochromic devices are demonstrated in a special pattern, and the high impact resistance of the device is verified. The results indicates that the proposed structure is a promising stretchable electrochromic device, which may have great potential for applications of chameleon-like camouflage functional materials and devices.