Image credit: PixelLabs from Pixabay.
Robots are getting better at seeing and moving through the world, but feeling it remains far harder. Now, researchers at the University of Cambridge say they have developed a miniature tactile sensor that could bring robotic touch much closer to that of human fingertips.
The device, described in Nature Materials, uses a novel composite made from graphene, liquid metal droplets and magnetically aligned nickel particles embedded in a soft silicone structure. Together, these materials allow the sensor to detect not only how hard a robot presses on something, but also the direction of forces, whether an object is slipping and even subtle surface textures.
Why touch is still hard for robots
Touch has long been a weak point in robotics. Human fingertips contain multiple types of mechanoreceptors that simultaneously sense pressure, vibration, texture and shear forces. Replicating that multidimensional sensitivity in artificial sensors, especially at very small scales, has proved difficult.
The Cambridge team, led by Professor Tawfique Hasan from the Cambridge Graphene Centre, tackled this by designing a porous, flexible material inspired by the microscopic structures of skin. They shaped it into tiny pyramid structures, each about 200 micrometres wide. When pressure is applied, electrical signals from electrodes beneath each pyramid allow the system to reconstruct the full three-dimensional force acting on the surface.
Detecting forces in three dimensions
The resulting sensor is highly sensitive, able to detect forces smaller than a micro-newton, roughly comparable to the weight of a grain of sand. At the same time, it can measure forces across a wide range and determine their direction with errors of less than two degrees.
In demonstrations, the sensors were integrated into robotic grippers. The robots were able to grasp delicate objects, such as thin paper tubes, without crushing them. Because the sensors detect tiny slip events, the system can adjust its grip in real time, a capability essential for dexterous manipulation.
From robotic hands to prosthetics
The technology could also prove valuable in prosthetic limbs, where realistic tactile feedback remains a major challenge. Highly sensitive miniature sensors could help artificial hands interact with objects more naturally and safely.
Beyond robotics and prosthetics, the researchers say similar sensor arrays could enable microrobots or surgical tools to manipulate tiny objects where conventional force sensors are too large.
With further miniaturisation, potentially down to tens of micrometres, the team believes future versions could approach the density of touch receptors in human skin. Additional sensing abilities, such as temperature and humidity, could eventually turn the technology into a fully-fledged “electronic skin” for robots.
Reference: Yun G, Chen Z, Chen Z, et al. Multiscale-Structured Miniaturized 3D Force Sensors. Nat Mater. Published online February 18, 2026:1-9. doi:10.1038/s41563-026-02508-7
Adapted from a story originally published on the Electrical Engineering website.