Transformative electronics reconfigure into wearables

A team working under Prof Jae-Woong Jeong from the School of Electrical Engineering at KAIST invented the multifunctional electronic platform that can mechanically transform its shape, flexibility, and stretchability. Reported in Science Advances, the platform us claimed to allow users to precisely tune its stiffness and shape.

"This new class of electronics will not only offer robust, convenient interfaces for use in both tabletop or handheld setups, but also allow seamless integration with the skin when applied onto our bodies," Prof Jeong said in a statement.

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The transformative electronics consist of a gallium metal structure, hermetically encapsulated and sealed within a soft silicone material, combined with electronics that are designed to be flexible and stretchable. The mechanical transformation of the electronic systems is specifically triggered by temperature changes that are controlled by the user.

"Gallium is an interesting key material. It is biocompatible, has high rigidity in solid form, and melts at a temperature comparable to the skin's temperature," said lead author Sang-Hyuk Byun, a researcher at KAIST.

Once the transformative electronic platform comes in contact with a human body, the gallium encapsulated inside the silicone changes to a liquid state and softens the whole electronic structure, making it stretchable, flexible, and wearable. The gallium then solidifies again once the structure is peeled off the skin, making the electronic circuits stiff and stable.

"This technology could not have been achieved without interdisciplinary efforts," said co-lead author Joo Yong Sim, who is a researcher with ETRI. "We worked together with electrical, mechanical, and biomedical engineers, as well as material scientists and neuroscientists to make this breakthrough."

This universal electronics platform allowed researchers to demonstrate applications that were highly adaptable and customisable, such as a multi-purpose personal electronics with variable stiffness and stretchability, a pressure sensor with tuneable bandwidth and sensitivity, and a neural probe that softens upon implantation into brain tissue.