- Secured next-generation neural interface technology capable of integrating XR and digital therapeutics

- Published in the internationally renowned journal *Nature Communications*

The University of Seoul announced that a research team led by Professor Sun Hong Kim from the Department of Chemical Engineering and Professor Dong-Wook Park from the School of Electrical and Computer Engineering, in collaboration with a research team led by Professor Yei Hwan Jung from Hanyang University, has developed a wearable textile-based electrical stimulation suit (TESS) that can simultaneously provide tactile stimulation and therapeutic functions to the entire body.

The findings of this study were published in the world-renowned journal “Nature Communications” (IF 15.7, top 5.6% in the JCR) and are highly regarded as a next-generation neural interface technology that integrates an electrophysiological stimulation-based haptic interface with therapeutic functions.

TESS, developed by the research team, is a fiber-based wearable system that provides electrical stimulation to the entire body. This technology enables full-body haptic feedback beyond existing devices that focus on the hands or specific body parts. Notably, it integrates haptic feedback, muscle/nerve stimulation-based therapy, and XR (AR/VR) interfaces into a single system. By precisely controlling the frequency and intensity of electrical stimulation, the research team successfully replicated various tactile sensations, such as touch, tickling, roughness, and pressure, and achieved a user recognition accuracy of approximately 90%.

In this study, the core material technology was developed by the research team led by Professor Sun Hong Kim (co-first author) at the University of Seoul. The team created a flexible, low-impedance electrode structure by combining a PEDOT:PSS-based conductive hydrogel (DMCH) with a silver (Ag)-based stretchable conductor (Ag-PU). This solution addressed issues associated with conventional electrodes, such as skin irritation, contact instability, and performance degradation with prolonged use, to achieve a high-performance wearable electrode for long-term wear. Furthermore, the electrode is recognized as a material platform capable of large-area application on the body, as it simultaneously offers high conductivity and biocompatibility.

△Flexible, low-impedance electrode structure combining a conductive hydrogel (DMCH) and stretchable conductor (Ag-PU), and a fiber-based wearable system utilizing this structure

In the circuit and system aspects, the research team led by Professor Dong-Wook Park (corresponding author) of the University of Seoul implemented the core technology. Dr. Ju-Hwan Kim, a postdoctoral researcher on the team (co-first author), made a key contribution to the development of an intelligent feedback control system that integrates real-time measurement of skin-electrode impedance, a garment-pressure-based sensing system, and an automatic voltage calibration algorithm. This enables the delivery of consistent tactile stimulation despite individual differences in body shape, changes in wearing pressure, and variations in skin condition.

△ Intelligent feedback control and flexible circuit system integrating garment pressure-based sensing and an automatic voltage calibration algorithm

The research team verified the system’s diverse application potential by conducting experiments such as haptic implementation in VR environments and alleviation of hand tremors through electrical stimulation. In particular, by simultaneously implementing therapeutic functions using electrical stimulation and a haptic interface, the system is expected to discover diverse applications in the fields of digital therapeutics, neurorehabilitation, and brain-computer interfaces (BCI) in the future.

Professor Sun Hong Kim of the University of Seoul stated, “The TESS system we have developed is a wearable neural interface platform that delivers precise electrical stimulation to the entire body and implements a consistent haptic interface based on pressure signal feedback.” Professor Dong-Wook Park added, “We plan to further develop this system and expand it into a next-generation neural interface that integrates neural signal acquisition and haptic feedback.”

This research was conducted with support from the Ministry of Science and ICT’s Global Basic Research Laboratory Program and Artificial Intelligence Semiconductor Excellence Talent Development Program (Institute of Information and Communications Technology Planning and Evaluation, IITP), the National Research Foundation of Korea (NRF), the Ministry of Education, the Seoul RISE Center of the Seoul Metropolitan Government, and Hanyang University.

△From left: Professor Sun Hong Kim and Dr. Ju-Hwan Kim of the University of Seoul; Ph.D. candidate Jin Hee Hwang of Hanyang University; Professor Dong-Wook Park of the University of Seoul; and Professor Yei Hwan Jung of Hanyang University