Scientists at the National University of Singapore (NUS) have developed a new type of electronic skin that can detect touch, sense damage, and repair itself—even while underwater.
The technology could make underwater robots, diving equipment, and wearable devices much more reliable in harsh environments.
The research, led by Assistant Professor Tan Yu Jun from the NUS College of Design and Engineering, was published in the journal Advanced Materials.
Working underwater is especially challenging for electronic devices. Sensors used by divers and underwater robots can easily be damaged by sharp rocks, shells, or other hazards.
Once damaged, these sensors often stop working and usually need to be replaced or repaired on land.
They also typically rely on batteries or other external power sources, which can limit their usefulness underwater.
The new system, called a self-healing magnetoelectric sensory system (SMES), solves several of these problems at once. It can detect touch and nearby objects without needing an external power supply. It can also recognize when it has been damaged and begin repairing itself automatically.
The researchers designed the system to mimic human skin. Just as our skin can sense touch, feel pain, and heal after an injury, this electronic skin responds when it is punctured or cut. The device contains a flexible, rubber-like material with tiny liquid-metal conductors. When damaged, the material’s electrical resistance quickly changes, signaling that something is wrong.
The material is also able to heal itself. If the damage is small, such as a needle puncture, the sensor can recover its original electrical performance within seconds without any outside help. Larger cuts take longer to repair, but simply pressing the damaged surfaces together starts the healing process. After enough time, the device regains its strength and sensing ability.
The electronic skin works especially well underwater, where many self-healing materials struggle. Tests showed that after healing, the material could recover nearly all of its performance underwater.
Another key feature is that the sensor powers itself. It generates electricity through electromagnetic induction—the same basic principle used in electric generators. Inside the sensor, a small magnet moves near a coil of liquid-metal wire whenever something touches or approaches the device. This movement creates a small electrical signal, allowing the sensor to detect pressure and nearby objects without using a battery.
The system also proved to be fast and durable. It responded to touch in about 41 milliseconds and continued working reliably after 10,000 repeated uses. It also maintained its sensing ability after spending 10 days underwater, including in water that simulated seawater.
To demonstrate its potential, the researchers built a smart diving glove equipped with the new electronic skin. Different hand gestures generated unique electrical signals that were sent wirelessly to a smartphone. The glove could communicate messages such as “Going up,” “Going down,” “Holding,” and “Help.” It also included warning lights that alerted the wearer if the glove had been seriously damaged.
The team also created a robotic hand fitted with the sensors. During underwater tests, the robotic hand successfully picked up and carried objects while detecting punctures from sharp shells and recovering from the damage.
The researchers hope the technology will eventually be used in underwater robots, prosthetic limbs, wearable electronics, and other soft machines that can sense damage and recover on their own, making them safer, longer-lasting, and better suited for challenging environments.
