NUS researchers have developed a groundbreaking self-healing magnetoelectric sensory system (SMES) that promises to revolutionize underwater technology. This innovative device, inspired by biological skin, can sense touch, detect damage, and autonomously repair itself, making it a game-changer for divers, underwater robots, and various other applications.
A Skin-Inspired Sensor
The SMES is a marvel of engineering, mimicking the protective and healing capabilities of biological skin. It consists of multiple layers, including a top damage-sensing layer and an electromagnetic sensing layer, both built on a stretchable, self-healing elastomer. When the sensor is damaged, its electrical resistance spikes, indicating an injury similar to pain in living tissue.
The secret to its self-healing ability lies in the reversible molecular interactions within the elastomer. When two damaged surfaces come together, molecular groups reconnect, allowing the material to heal itself. This process is remarkably efficient, with the sensor recovering its original performance within seconds after needle pricks and regaining full functionality after a longer healing period for more severe cuts.
Self-Powered and Durable
What sets the SMES apart is its self-powered nature. It generates electrical signals through electromagnetic induction, eliminating the need for an external power source. A small magnet and a coil of liquid-metal wire create a voltage when an object presses on the sensor or moves nearby, enabling proximity and tactile sensing.
The sensor's response time is impressive, at approximately 41 milliseconds, and it maintains stable output after 10,000 cycles of usage, surpassing the benchmark for electronic skins. Its durability is further showcased by its ability to retain damage-detection and self-repair capabilities even when fully submerged in water, a challenging environment for many materials.
Real-World Applications
The team demonstrated the SMES's potential through two prototypes. The first is a smart diving glove that allows divers to communicate wirelessly using hand gestures, transmitting commands such as 'Normal', 'Going up', and 'Help' via Bluetooth to a smartphone. Red LEDs on the glove serve as a visual warning when severe damage is detected.
The second prototype is a robotic hand equipped with the SMES technology for underwater tasks. It can grasp objects, transport them, and detect damage in real-time, indicating the severity of the issue with green, yellow, and red LEDs. During testing, the robotic hand successfully handled sharp shells, demonstrating its ability to self-repair from puncture damage.
Looking Ahead
Assistant Professor Tan Yu Jun, the research leader, envisions a future where SMES technology is integrated into real robots, prosthetics, and wearable devices. The ultimate goal is to create soft machines that can sense their surroundings, recognize damage, and recover their functions, much like living skin, even in unpredictable environments.
This breakthrough technology has the potential to transform underwater operations, making them safer and more efficient. As the research progresses, we can expect to see even more innovative applications of this remarkable self-healing sensory system.
