A doctoral student at the Technion has invented a soft electricity-conducting polymer that is elastic and waterproof, and can heal itself in the event of an “injury,” even if cut apart.
By Yakir Benzion, United With Israel
Technion doctoral student Muhammad Khatib is working on his PhD in chemical engineering and developed a new plastic that is a major leap forward in the development of artificial skin.
Khatib has been working on a new polymer to develop advanced sensors for monitoring temperature, pressure, and acidity for a range of future applications in the fields of robotics, prosthetics (artificial limbs) and wearable devices.
Working with lab partners and under the guidance of Technion Professor Hossam Haick, Khatib’s new elastomer – a resilient polymer – is strong, water resistant, conducts electricity and is super elastic. It can stretch to 11 times its original length without tearing.
However, the amazing feature of the new polymer is that it can heal itself in water.
Khatib posted a video on YouTube showing a rectangular piece of the polymer floating in a dish of water. The piece of plastic is picked up, sliced in half, and then put back in the water and pushed back together along the two cut edges. Within a short time the plastic has totally joined itself back together and is not only whole again, but can be stretched without breaking along the seam where it ‘healed’ itself.
The new elastomer has a huge potential for use in soft, dynamic electronic devices that come into contact with water. In the event of physical damage to the polymer while it’s submerged, it can heal itself and prevent electrical current from leaking from the device into the water.
Khatib recently published the results in the journals of Advanced Materials and Advanced Functional Materials.
“The new sensory platform is a universal system that displays stable functioning in both dry and wet environments, and it is capable of containing additional types of chemical and physical (electronic) sensors,” Khatib explained. “Both projects that were now published pave the way for new paths and new strategies in the development of skin-inspired electronic sensing platforms that can be integrated into wearable devices and electronic skins for advanced robots and artificial organs.”
Khatib’s research is built on the natural evolutionary process through which the skin of mammals developed into a sensory platform that on one hand has high sensitivity to environmental stimuli, and on the other hand is resistant to hostile conditions such as salinity, heat, cold, stretching, and folding. A great deal of effort has been invested in developing artificial electronic materials that are inspired by natural skin to make devices with similar properties.
The potential applications are huge for the fields of robotics and human-machine interfaces that require developing soft materials whose functioning is not harmed by distortions or tears. Because soft materials tend to get damaged over time, new materials that can heal themselves, just like human skin does after an injury, are an exciting development.
Khatib is taking advantage of the new polymer’s promising traits to develop artificial electronic skin that incorporates features like selective sensing, resistance to water, self-monitoring and self-healing. Nanometric materials embedded in the polymer can selectively and simultaneously monitor various environmental variables such as pressure, temperature, and acidity. Khatib’s piece-de-resistance is the autonomous self-healing feature of the new artificial skin.