Stamp‐Like Energy Harvester and Programmable Information Encrypted Display Based on Fully Printable Thermoelectric Devices

Abstract Thermoelectric (TE) devices exhibit considerable application potential in Internet of Things and personal health monitoring systems. However, TE self‐powered devices are expensive and their fabrication process is complex. Therefore, large‐scale preparation of the TE devices remains challenging. In this work, simple screen‐printing technology is used to fabricate a user‐friendly and high‐performance paper‐based TE device, which can be used in both stamp‐like paper‐based TE generators and infrared displays. When used as a paper‐based TE generator, an output power of 940.8 µW is achieved with a temperature difference of 40 K. The programmable infrared pattern based on the TE array display could be used to realize encryption and anti‐counterfeiting properties. Moreover, a visual extraction algorithm is used to develop a mobile application for processing and decoding the infrared quick response code information. These findings offer an exciting approach to using paper‐based TEGs in applications such as energy harvesting devices, optical encryption, anti‐counterfeiting, and dynamic infrared display.