A new concept 3D printing technology has been developed that allows for the free drawing of soft conductors with high elasticity and conductivity, raising expectations that it can be applied to skin electronics that are soft like skin in the future.

The Ministry of Science and ICT (Minister Lee Jong-ho) announced on the 21st that a research team led by Dr. Seung-Jun Jeong at the Soft Convergence Materials Research Center of the Korea Institute of Science and Technology (President Seok-Jin Yoon, hereinafter 'KIST') has succeeded in realizing user-customized freeform skin electronics using a new concept omnidirectional printing process technology.

This research was conducted with the support of the Ministry of Science and ICT's Nanomaterials Technology Development Project, KIST's major projects, and the Sejong Science Fellowship, and the results of the research were published as a cover article in Nature Electronics (IF 33.255) on April 21.

Unlike conventional silicon-based semiconductor devices, the advancement of skin electronics, which is soft like skin, is enabling human-machine interfaces that closely adhere to the human body, such as real-time health signal monitoring and neural circuit interfaces.

Skin electronics requires freeform designs and customized processes tailored to the user's body and intended use, while simultaneously necessitating the implementation of complex three-dimensional circuits for high integration. However, existing semiconductor processes or 3D printing technologies had limitations in producing circuits that could be freely deformed to fit the body with various curved surfaces.

A research team led by Dr. Seung-Jun Jeong at KIST has developed a technology capable of directly drawing soft conductors, a core material for skin electronics, in three dimensions, and using this, announced freeform skin electronics that operate stably even under mechanical deformation.

When fabricating circuits with three-dimensional structures using previously reported conductive inks, there were limitations such as the materials easily breaking or degrading in performance due to external impact or mechanical deformation. The research team developed a soft conductive material that utilizes the emulsifying action of the ink to enable free 3D printing in all directions while simultaneously drastically reducing the problem of nozzle clogging.

This allows for the free and direct drawing of soft electrodes in all directions that maintain high conductivity even when stretched by more than 150%, enabling the fabrication of complex three-dimensional flexible circuits tailored to the user.

The soft conductive material developed in this study is currently being reviewed for mass production potential through a specialized materials company, and it is expected to have a ripple effect if utilized in the fields of wearable and biomedical devices, soft robots, and the printing industry.

Dr. Seung-Jun Jeong of KIST stated, “The soft electrode material and process technology developed through this research will overcome the design limitations of existing standardized electronic devices and contribute to the production of wearable devices with new form factors. Furthermore, we expect that it can be utilized in fields such as the Internet of Things, interfaces for virtual and augmented reality, and bio-interfaces.”