Scientists from the National University of Singapore have taken inspiration from jellyfish to create an electronic skin.
Just like a jellyfish, the electronic skin is transparent, stretchable, touch-sensitive and self-healing in aquatic environments. It can be used in everything from water-resistant touchscreens to aquatic soft robots.
“One of the challenges with many self-healing materials today is that they are not transparent and they do not work efficiently when wet,” said Materials Science and Engineering Assistant Professor Benjamin Tee. “These drawbacks make them less useful for electronic applications such as touchscreens which often need to be used in wet weather conditions.”
He continued, “With this idea in mind, we began to look at jellyfishes — they are transparent, and able to sense the wet environment. So, we wondered how we could make an artificial material that could mimic the water-resistant nature of jellyfishes and yet also be touch sensitive.”
They succeeded by creating a gel comprising a fluorocarbon-based polymer with a fluorine-rich ionic liquid. When combined, the polymer network interacts with the ionic liquid via highly reversible ion–dipole interactions, which allows it to self-heal.
Elaborating on the advantages of this configuration, Asst Prof Tee explained, “Most conductive polymer gels such as hydrogels would swell when submerged in water or dry out over time in air. What makes our material different is that it can retain its shape in both wet and dry surroundings. It works well in sea water and even in acidic or alkaline environments.”
The electronic skin is created by printing the novel material into electronic circuits. As a soft and stretchable material, its electrical properties change when touched, pressed or strained. “We can then measure this change, and convert it into readable electrical signals to create a vast array of different sensor applications,” Asst Prof Tee added.
Soft robots, and soft electronics in general, aim to mimic biological tissues to make them more mechanically compliant for human-machine interactions. In addition to conventional soft robot applications, this novel material’s waterproof technology enables the design of amphibious robots and water-resistant electronics.
One further advantage of this self-healing electronic skin is the potential it has to reduce waste. Millions of tonnes of electronic waste from devices like broken mobile phones are generated globally every year. The scientists hope to create a future where electronic devices made from intelligent materials can perform self-repair functions to reduce the amount of electronic waste in the world.