Advancements in transfer printing techniques for flexible electronics: adjusting interfaces and promoting versatility

The burgeoning interest in flexible electronics necessitates the creation of patterning technology specifically tailored for flexible substrates and complex surface morphologies. Among a variety of patterning techniques, transfer printing emerges as one of the most efficient, cost-effective, and scalable methods. It boasts the ability for high-throughput fabrication of 0-3D micro- and nano-structures on flexible substrates, working in tandem with traditional lithography methods. This review highlights the critical issue of transfer printing: the flawless transfer of devices during the pick-up and printing process. We encapsulate recent advancements in numerous transfer printing techniques, with a particular emphasis on strategies to control adhesion forces at the substrate/device/stamp interfaces. These strategies are employed to meet the requirements of competing fractures for successful pick-up and print processes. The mechanism, advantages, disadvantages, and typical applications of each transfer printing technique will be thoroughly discussed. The conclusion section provides design guidelines and probes potential directions for future advancements.