Interfacial Liquid Film Transfer Printing of Versatile Flexible Electronic Devices with High Yield Ratio

Emerging flexible electronic devices differ widely in terms of material, shape, scale, and structure. The conventional solid-contact stamp transfer printing method easily causes cracks and interfacial delamination in large-area, intricately-patterned multilayered devices. Liquid film transfer printing (LTP) is presented as a strategy to obtain flexible devices with a high yield ratio regardless of the device material, scale, shape, and structure. In this technique, the liquid film is used to hydrolyze and break the chemical bonds between the film and silicon wafer substrate. Thus, there is less stress on the device during the transfer process. In addition, the buoyancy and surface tension of the liquid film help the flexible device to unroll itself on the liquid surface. In the experiments, flexible devices of different types and with extreme properties consistently achieved a transfer printing yield ratio of 98.57%. The sensitivity of temperature sensor change before and after LTP is less than 2%. The real-time and visualized comparisons of the stress distribution and evolution during LTP and solid-contact methods demonstrated that the LTP maximum strain is 70% smaller than the latter method. Thus, LTP has great potential for sophisticated and system-level flexible device transfer printing and integration.