Reserachers in the US have developed a new type of malleable, self-healing and fully recyclable electronic skin which could be used in robotics, prosthetics and biomedical devices.
Electronic skin (e-skin), is a thin and translucent material that can mimic the function and mechanical properties of human skin.
The e-skin developed at the University of Colorado in Boulder has sensors embedded to measure pressure, temperature, humidity and air flow. The skin uses a novel type of covalently bonded dynamic network polymer, known as polyimine, that has been laced with silver nanoparticles to provide better mechanical strength, chemical stability and electrical conductivity.
Assistant Professor Jianliang Xiao, joint-research lead on the project at the University of Boulder said: “The chemical bonding of the polyimine we use allows the e-skin to be both self-healing and fully recyclable at room temperature,
“Given the millions of tons of electronic waste generated worldwide every year, the recyclability of our e-skin makes good economic and environmental sense.”
The e-skin, including the sensors, is also able to “self-heal” by mixing three commercially available compounds in ethanol. It can also be easily shaped to curved surfaces like human arms and robotic hands by applying moderate heat and pressure to it without introducing excessive stresses.
CU Boulder chemistry and biochemistry Associate Professor Wei Zhang said: “Let’s say you wanted a robot to take care of a baby. In that case you would integrate e-skin on the robot fingers that can feel the pressure of the baby. The idea is to try and mimic biological skin with e-skin that has desired functions.”
To recycle the skin, the device is soaked into a recycling solution, which degrades the polymers into oligomers, polymers with polymerization degree usually below 10 and monomers, small molecules that can be joined together into polymers, that are soluble in ethanol. The silver nanoparticles sink to the bottom of the solution.
“The recycled solution and nanoparticles can then be used to make new, functional e-skin,” said Xiao.
The study was published today in the journal Science Advances.