Reliable transfer enabled by UV-curable stamp with tunable rigidity

Transfer printing enables the fabrication of flexible electronics by transferring devices from donor to receiver substrates. However, using an elastic stamp can cause strain and damage during transfer. A rigid stamp can solve this issue, but rigid materials are unsuitable for flexible electronics. In this study, we present a transfer approach using a UV-curable polyurethane acrylate film as a stamp with solvent-induced mechanical properties, from rigidity to elasticity. During the transfer, the UV-curable film is tuned to be rigid to prevent damage to the transferred materials caused by strain during peeling. The approach enables the intact transfer of metallic structures, including various multi-scale Ag patterns with the highest resolution of 10 mu m, high transfer yield, and scalability. The interfacial mechanisms of metal transfer were analyzed. The results demonstrate that surface modification through increasing contact angles, improve the stability of metal transfer. When soaked in ethanol, the film becomes soft and elastic, making it an ideal flexible substrate for fabricating electronics, especially for applications in sensing, healthcare, and artificial skin.