KAIST research team develops sweat-resistant wearable robot sensor

Led by Professor Jae-Woong Jung from the KAIST School of Electrical Engineering (EE) and Professor Jung Kim from the KAIST Department of Mechanical Engineering (ME), the joint research team has successfully developed a stretchable and adhesive microneedle sensor capable of electrically sensing physiological signals at a high level without being affected by the user's skin condition. This technology holds great promise for improving the precision and effectiveness of rehabilitation treatments involving wearable robots.

Existing sensors have often faced challenges related to deteriorating signal quality over time and susceptibility to the wearer's skin conditions, limiting their reliability for long-term use. Additionally, their mechanical hardness has contributed to noise, as they struggle to adapt to the deformation of the skin. These limitations have hindered the widespread and dependable use of wearable robots in the field of rehabilitation.

The recently developed sensor technology is poised to overcome these limitations by enabling long-term, high-quality EMG measurements. It utilizes a stretchable and adhesive conducting substrate integrated with microneedle arrays, which can effortlessly penetrate the stratum corneum without causing discomfort to the wearer. This approach allows the sensor to maintain its performance over an extended period, regardless of the wearer's changing skin conditions. Importantly, it eliminates the need for a preparation step to remove sweat and dead cells from the wearer's skin surface.

The research team achieved this by integrating microneedles into a soft silicon polymer substrate. These flexible microneedles can penetrate the stratum corneum, which has high electrical resistance, effectively reducing contact resistance with the skin and ensuring high-quality electrophysiological signals even in the presence of contaminants. The soft and adhesive conducting substrate adapts to the skin's surface, stretching with the wearer's movement to provide a comfortable fit and minimize noise caused by movement. To validate the usability of this innovative sensor, the research team conducted a motion assistance experiment using a wearable robot.

Professor Jae-Woong Jung, who led the research, emphasized that "the developed stretchable and adhesive microneedle sensor can stability detect EMG signals without being affected by the state of a user’s skin. Through this, we will be able to control wearable robots with higher precision and stability, which will help the rehabilitation of patients who use robots." This advancement is expected to significantly enhance the precision and stability of wearable robots, ultimately benefiting patients undergoing rehabilitation.

MEDICA-tradefair.com Source: KAIST (Korea Advanced Institute of Science and Technology)