A KAIST research team has developed a pressure sensor that remains stable and interference-free even in wet conditions, achieving human-like tactile sensitivity.
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Advancements in robotics have enabled machines to handle delicate objects, such as eggs, with impressive precision. This is largely thanks to highly integrated pressure sensors that provide detailed tactile feedback. However, even the most sophisticated robots face challenges in accurately detecting pressure in environments involving water, bending, or electromagnetic interference. To address this issue, the KAIST team developed a sensor that functions reliably on wet surfaces, such as a water-covered smartphone screen.
KAIST, led by President Kwang Hyung Lee, announced on March 10th that a research team headed by Professor Jun-Bo Yoon from the School of Electrical Engineering has successfully developed a high-resolution pressure sensor resistant to external disturbances, including "ghost touches" caused by moisture on touchscreens.
Capacitive pressure sensors, commonly used in touch systems due to their simple structure and durability, play a crucial role in human-machine interface (HMI) technologies found in smartphones, wearable devices, and robotics. However, these sensors are prone to malfunctions caused by water droplets, electromagnetic interference, and curved surfaces. To tackle these issues, the KAIST team analyzed the root causes of interference in capacitive pressure sensors and found that the "fringe field"—an electric field at the sensor’s edges—was particularly vulnerable to external disturbances.
The researchers determined that the best way to mitigate this issue was to suppress the fringe field. Through theoretical analysis, they found that reducing the electrode spacing to the nanometer scale could effectively minimize the fringe field to below a few percent. Using proprietary micro/nanofabrication techniques, the team developed a nanogap pressure sensor with an electrode spacing of just 900 nanometers (nm). This new sensor accurately detected pressure regardless of the material applying force and remained unaffected by bending or electromagnetic interference.
Additionally, the team implemented an artificial tactile system utilizing the sensor’s unique properties. Human skin contains specialized pressure receptors called Merkel’s disks, which allow for precise touch sensitivity. To replicate this, the researchers needed a sensor capable of exclusively detecting pressure—a challenge that previous technologies had not overcome.
Professor Yoon’s team succeeded in developing a sensor with a density comparable to Merkel’s disks, enabling wireless, high-precision pressure sensing. To explore its potential applications, they also created a force touch pad system, which demonstrated the ability to capture pressure magnitude and distribution with high resolution and without interference.
Our nanogap pressure sensor operates reliably even in rainy conditions or sweaty environments, eliminating common touch malfunctions. We believe this innovation will significantly enhance everyday user experiences. This technology has the potential to revolutionize various fields, including precision tactile sensors for robotics, medical wearable devices, and next-generation augmented reality (AR) and virtual reality (VR) interfaces.
Jun-Bo Yoon, Professor, School of Electrical Engineering, Korea Advanced Institute of Science and Technology
Journal Reference:
Yang, J.-S., et. al. (2025) Interference-free nanogap pressure sensor array with high spatial resolution for wireless human-machine interfaces applications. Nature Communications. doi.org/10.1038/s41467-025-57232-8