NUS researchers have developed a groundbreaking self-healing, water-resistant e-skin technology that could revolutionize underwater robotics and human-machine interfaces. This innovative magnetoelectric sensory system (SMES) combines self-powered touch and proximity sensing with built-in damage detection and autonomous self-repair, making it highly durable and self-sufficient in harsh underwater environments.
The SMES is inspired by biological skin, which can feel touch and heal itself after injury. It consists of multiple layers, including a top damage-sensing layer and an electromagnetic sensing layer, both built on a stretchable, self-healing elastomer laced with liquid-metal conductors. When damaged, the electrical resistance of the top layer spikes, mimicking the pain response in living tissue. The material's soft nature allows for reversible molecular interactions, enabling self-healing when two damaged surfaces come into contact.
The self-healing elastomer achieves impressive elastic recovery and healing efficiency, even in water. It can recover up to 92% of its original performance after needle pricks and regain full functionality within seconds. For more severe damage, brief mechanical pressure triggers initial repair, and the sensor regains full functionality after a longer healing period. This technology has the potential to extend the lifespan of underwater devices and enhance safety for divers.
One of the key advantages of the SMES is its self-powered design. It generates electrical signals through electromagnetic induction, eliminating the need for an external power source. This is particularly beneficial in underwater settings where battery access is limited. The sensor demonstrated exceptional response times and mechanical durability, maintaining stable output after thousands of cycles of usage, even in simulated seawater.
The research team showcased the SMES's potential through two prototypes. The first is a smart diving glove that enables wireless underwater communication using hand gestures. Sensors on each fingertip generate distinct voltage patterns for different commands, allowing divers to relay status updates without speaking. The glove also features a damage sensor with red LEDs that light up when severe damage is detected.
The second prototype is a robotic hand equipped with the SMES technology for underwater grasping and delivery tasks. It can detect and recover from puncture damage caused by sharp shells, ensuring its functionality in harsh environments. The hand's damage status is indicated by three LEDs, providing real-time feedback to users.
Assistant Professor Tan Yu Jun, the lead researcher, emphasizes the potential of this technology. He envisions integrating the SMES into real robots, prosthetics, and wearable devices, enabling them to sense their surroundings, recognize damage, and recover their function, much like living skin. This development opens up exciting possibilities for the future of underwater robotics and human-machine interaction.
