In the quest to make electronic devices more environmentally friendly, a team of researchers from the University of Colorado at Boulder (USA) has created an electronic skin that can be completely recycled . Also, it can fix itself if it breaks.
The device, described in the journal Science Advances , is basically a thin film equipped with sensors that can measure blood pressure, temperature, humidity and air flow. The film is made up of three commercially available compounds mixed in a matrix and bound together with silver nanoparticles: when the electronic skin is cut in two, the addition of the three compounds to the “wound” allows the electronic skin to ‘heal’ by means of recreating chemical bonds between the two sides.
In this way, the matrix is restored and the electronic skin is like new. In the event that the electronic skin is damaged in such a way that there is no possibility of repair, it can be soaked in a solution that dissolves it, and the materials can be reused to create a new electronic skin film. In the future, this innovative 100% recyclable electronic skin could be used in prosthetics, robots or smart textiles.
The e-skin revolution
Many labs around the world are developing electronic skins (e-skins). One of them, created in Europe, allows users to manipulate virtual objects without touching them, through the use of magnets. Another, developed in Japan, can turn a smart shirt into a motion controller for video games. What does this electronic space skin have? It’s special because it’s recyclable, and that’s an added bonus when you consider that, for example, more than $ 22 billion of electronic waste was created in 2014 in the US alone. All of these PCBs, transistors, and hard drives They may contain toxic chemicals that must be disposed of properly.
“This particular device will not produce any waste,” says study co-author Jianliang Xiao. “We want electronics to be environmentally friendly.”
Therefore, if the electronic skin is severely damaged and cannot repair itself, it can be recycled using a “recycling solution”. This solution dissolves the matrix into small molecules, allowing the silver nanoparticle to sink to the bottom. All materials can be reused to create another electronic patch.
Complete recycling takes around 30 minutes at 60ºC or 10 hours at room temperature. Healing / repair occurs even faster: half an hour at room temperature, or in a few minutes 60ºC, according to the researchers.
Yes indeed. Electronic skin is not perfect. It is soft, but not as elastic as human skin.
Scientists are working to make the device more scalable, making it easier to manufacture and insert into prosthetics or robots. But the recycling factor is undoubtedly the most interesting of all.
“ We face pollution problems every day. It is important to preserve our environment and make sure that nature can be very safe for us and our children,” says Xiao.
Reference: “Rehealable, fully recyclable, and malleable electronic skin enabled by dynamic covalent thermoset nanocomposite” Science Advances (2018). advances.sciencemag.org/content/4/2/eaaq0508
Image credit: Jianliang Xiao / University of Colorado Boulder
