Inkjet printing for smart electrochromic devices

Electrochromic technology has recently made many achievements in research and commercialization. Electrochromic devices are being developed based on various coating and printing methods for multipronged applications, and have great potential for next-generation flexible electronics. Compared to other coating and printing techniques, inkjet printing (IJP) enables non-contact patterning on a variety of substrates by programming the movement of the printing nozzle. IJP has great advantages in printing smart electrochromic devices because of its low cost, high resolution, high material utilization rate, and applicability to various large-size substrates. In this review, the principles and process of IJP and the latest progress of IJP in electrochromic devices are summarized in detail. IJP of electrochromic materials, conductive contacts, and blocking layers are discussed. IJP assisted fabrication of smart electrochromic displays, flexible and stretchable electrochromic devices, electrochromic-energy storage, smart windows, and others are also demonstrated. The problems and challenges faced by IJP electrochromic devices are emphasized, and the future development trends are prospected. This review aims at further promoting the development of IJP for smart electrochromic devices and encouraging future applications of IJP and electrochromic devices in the era of Internet of Things.