A New Way to Transfer Print Flexible Electronics

Researchers at the Institute for Basic Science (IBS) in South Korea created an innovative dry transfer printing technique for flexible electronic devices. This method allows for the transfer of high-quality electronic materials without damage.

High-quality electronic materials are typically processed at high temperatures to create crystalline structures and electrical properties. The high temperatures make it challenging to process the materials directly on flexible or stretchable substrates. The electronics are “transfer printed” from solid to soft substrate, but there are toxic chemicals and potential mechanical damage during the transfer process to deal with.

To overcome previous challenges, the team developed a damage-free dry transfer printing method that controls stress within thin films. By adjusting sputtering parameters, the team controlled the type and magnitude of stress within the film and created bilayer structures with varying stresses to maximize the stress gradient. They applied additional tensile stress through external bending deformation, maximizing the strain energy release rate and allowing delamination.

The researchers demonstrated that greater stress gradients within thin films result in larger bending moments, causing them to curl and transform from a two-dimensional (2D) thin film into a three-dimensional (3D) structure. 3D structures can be adjusted by the adhesive layer pattern during transfer printing so that the design and fabrication of desired structures meet various requirements.

Transfer printing technology has applications across fields such as flexible electronics, optoelectronics, bioelectronics, and energy devices.