Robots are becoming increasingly capable of handling delicate objects — like eggs — with remarkable precision. This is largely due to advanced pressure sensors that give them a sense of touch. However, operating accurately in wet or harsh environments has remained a challenge. Water, bending surfaces, and electromagnetic interference often cause existing sensors to malfunction.
A research team at KAIST (Korea Advanced Institute of Science and Technology) has now addressed this issue. They have developed a highly sensitive pressure sensor that remains stable and interference-free even when wet — making robotic touch more human-like than ever before.
Solving Pressure Sensing Challenges in Wet Conditions
Capacitive pressure sensors are commonly used in human-machine interface (HMI) technologies — from smartphones and wearable devices to robotic systems. While durable and simple in design, they face key limitations:
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Water interference, which can cause accidental touches
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Electromagnetic interference, disrupting signal accuracy
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Curved surfaces, which make consistent pressure detection difficult
To overcome these issues, KAIST researchers focused on reducing the fringe field — the electric field at the sensor’s edges that is particularly vulnerable to outside disturbances.
Through careful analysis, they discovered that minimizing electrode spacing to the nanometer scale could drastically reduce this fringe field. Using advanced micro and nanofabrication techniques, they created a nanogap pressure sensor with electrode spacing as small as 900 nanometers.
Human-Like Touch Sensitivity Achieved
The new sensor reliably detects pressure regardless of external conditions — including rain, sweat, or bending. It offers:
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High-resolution pressure sensing
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Resistance to water and electromagnetic interference
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Stable performance on curved or flexible surfaces
Inspired by human skin’s Merkel’s disks, which enable precise touch sensitivity, the KAIST team also replicated this functionality by developing an artificial tactile system. Their sensor now matches the density of Merkel’s disks and delivers wireless, high-precision pressure detection.
Next-Gen Applications on the Horizon
To demonstrate its potential, the researchers created a force touch pad system using their new sensor. This system accurately captures pressure magnitude and distribution without interference, paving the way for innovative uses in:
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Robotics: precision tactile sensors
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Medical wearables: accurate and reliable health monitoring
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AR and VR interfaces: immersive, touch-sensitive experiences
With this innovation, KAIST researchers are bringing robots and human-machine interfaces closer to truly natural, human-like touch — even in the most challenging environments.
