Robots in the future could have skin that changes color after being touched: the idea comes from the golden turtle beetle, native to the Americas.
Much has been written in recent years about artificial skin. It is, in fact, a rapidly evolving field. Many researchers are engaged in developing extremely thin electronic systems equipped with sensors that are not only flexible, but also cheap enough to be produced on a large scale.
The latest research in this regard comes from the Computer Science and Artificial Intelligence Laboratory at MIT in Boston. Scientists have printed a 3D device that can respond to mechanical stress – such as being touched – by changing the color on the part of the surface where the “touch” occurred. The idea is that these kinds of systems could be used to allow robots to experience the world around them in a way more similar to humans: to detect pressure, temperature and other stimuli through their skin. But it could also find applications beyond robotics.
Nature is a great source of inspiration
The idea, as mentioned, was “borrowed” – as is often the case – from nature and, specifically, the golden turtle beetle. “Sensor networks and interconnections in nature,” explains Subramanian Sundaram who led the project, “are called sense-motor pathways.” “We were trying to figure out if it was possible to replicate these sense-motor pathways within a 3D printed object, so we chose the simplest organism we could find,” adds the MIT researcher. The result is a T-shaped device made of elastic plastic with a silver strip mounted on the surface and featuring a stiffer plastic section that houses two printed transistors and a “pixel,” which is a semiconductor polymer that changes color when the silver strip is stretched. The device is powered by a standard 1.5V battery.
The study is still in its infancy
The device was made via a 3D printer developed by the researchers themselves, using two different print heads – one for hot substances and the other for cold ones – and diodes that emit ultraviolet light to harden the printed substances. The MIT device, at this time, can run for about two months, but the researchers are confident that by replacing some components they could increase its autonomy. But, as Subramanian Sundaram admits, this is still an early stage of their research.