The Korea Advanced Institute of Science and Technology (KAIST) announced on the 23rd that a research team led by Professor Inkyu Park from the Department of Mechanical Engineering, in collaboration with the Electronics and Telecommunications Research Institute (ETRI) under the National Research Council of Science & Technology (NST), has developed an innovative technology that overcomes the structural limitations of existing tactile sensor technology.
The core of this joint research is the implementation of a customized tactile sensor that simultaneously ensures flexibility, precision, and repetitive durability by applying a thermally-formed three-dimensional electronic structure (T3DE). The platform is notable for overcoming the structural problems of soft elastomer-based sensors, such as slow response times, high hysteresis, and creep errors (where materials slowly deform under prolonged force), while still operating precisely in various environments.
The T3DE sensor is fabricated by forming precise electrodes on a two-dimensional film and then shaping it into a three-dimensional structure using heat and pressure. The design of the sensor, particularly the upper electrodes and supporting legs, allows for mechanical property adjustments based on intended use. By adjusting microstructural parameters such as thickness, length, and number of these supporting legs, the sensor’s Young’s modulus can be extensively set from 10 Pa to 1 MPa, resembling the stiffness of biological tissues like skin, muscles, and tendons, which makes it useful as a sensor for direct biological interfaces.
The newly developed T3DE sensor utilizes air as a dielectric to reduce power consumption and demonstrated excellent performance in terms of sensitivity, response speed, thermal stability, and repeat precision. Experimental results showed that the sensor maintained a sensitivity of 5,884 kPa⁻¹, a response time of 0.1 ms (less than 1/1000th of a second), hysteresis below 0.5%, and a precision of over 99.9% even after 5000 repeated measurements.
The research team demonstrated the sensor’s application by configuring a high-resolution 40×70 array of 2800 compact sensors to visualize the pressure distribution on the sole of the foot in real-time during movement and confirmed its potential for evaluating vascular health through wrist pulse measurements. Additionally, it achieved results in sound detection experiments on par with commercial acoustic sensors. Due to its accuracy and speed in measuring foot pressure, pulse, and sound, this sensor can be applied in various fields, including exercise, health, and sound detection.
T3DE technology has also been applied to augmented reality (AR)-based surgical training systems. Different Young’s moduli were assigned to each sensor element to replicate the stiffness of real biological tissues closely. The system provides simultaneous visual and tactile feedback based on the pressure applied during a surgical incision and includes real-time risk warnings if cuts are too deep or contact is made with dangerous areas. This is evaluated as a technology that can significantly enhance the immersion and accuracy of medical education.
Professor Inkyu Park stated, “This sensor can be precisely adjusted from the design stage to operate stably in various environments,” adding that it could be used in various fields such as everyday life, medicine, rehabilitation, and virtual reality.