A new transfer technology has been developed that separates high-performance electronic components from substrates without damage, much like peeling off a sticker.

The research team of Kim Dae-hyung, deputy research director (professor of chemical and biological engineering at Seoul National University) and Lee Sang-kyu, principal researcher at the Nanoparticle Research Group of the Institute for Basic Science (IBS, President Noh Do-young), announced on the 25th that they had jointly developed a damage-free dry transfer technology with the team of Professor Kim Ji-hoon at Pusan National University.

It is expected to be widely applied in the production of high-performance electronic devices as it can significantly reduce the time and cost required for transcription.

High-performance devices are often fabricated on rigid substrates that operate reliably even at high temperatures. To create flexible electronic devices, a transfer process is essential to separate components on a rigid substrate and transfer them to a flexible substrate.

The existing transfer process used chemicals to remove the layer (sacrificial layer) existing between the substrate and the device.

Because it uses strong and toxic chemicals, it is not good for workers or the environment, and it is difficult to avoid damage to components.

To solve this problem, methods such as removing the element from water or using lasers and heat have been developed, but they still require expensive equipment or separate post-processing and have limitations in that they can only be applied in certain environments.

The IBS research team developed a 'damageless dry transfer' method that controls the properties of the substrate itself to easily detach the device without using wet chemicals or damaging the device.

First, the research team created a substrate by stacking two layers of thin films with different stresses (force generated inside a deformed object when an external force is applied).

The substrate was then bent to maximize the strain energy release rate of the thin film. If the strain energy release rate exceeds the interfacial strength between the device and the substrate, peeling occurs easily.

After fabricating a component on the substrate manufactured in this way, a stamp is applied, and by bending the substrate and lifting the stamp, the component can be easily separated from the substrate. Transfer is completed when the removed component is transferred to the desired substrate.

“The transfer method proposed by our research team has the advantages of not using toxic substances, causing little damage to the device, requiring no post-processing, and having a short transfer time,” explained co-first author and senior researcher Shin Yun-soo. “It has great potential for use because it can transfer not only large areas but also micro-sized patterns.”

The research team also showed that two-dimensional thin films with various patterns can be transformed into three-dimensional structures. Depending on the pattern of the adhesive layer of the substrate to which the separated element is attached, it can be changed into a three-dimensional structure, and by utilizing this, various structures can be created as needed.

Dr. Sang-Kyu Lee, co-corresponding author, said, “Unlike previous studies, the core of this study is that we developed a damage-free dry transfer printing technology by controlling only the material properties.” He added, “We plan to conduct follow-up research on the manufacture of various devices with three-dimensional structures by utilizing the characteristic of being able to transform a two-dimensional thin film into a three-dimensional structure.”

“Transfer technology is applied to many fields, including soft electronics, optoelectronics, bioelectronics, and energy devices,” said Vice President Kim Dae-hyung, who led the research. “We expect that the damage-free dry transfer technology will be of great help in producing new high-performance electronic devices.”

The research results were published on June 21 in the online edition of 'Nature Materials (IF 41.2),' the world's top academic journal.