Although human skin can typically repair itself after damage, acute injuries can permanently interfere with some or all of skin's sensory capabilities. Current skin-repair therapies cannot restore those capabilities, so researchers have been searching for solutions. Flexible artificial skin technologies have been developed to support biocompatible electronic devices and sensors to imitate the natural functions of human skin. However, these wearable electronics are limited because they require an external energy source.

One solution may be found in a new type of artificial skin developed by a research team led by Professor Joondong Kim of Incheon National University in Korea. The artificial skin was produced using flexible and transparent thin layers of zinc oxide (ZnO), nickel oxide (NiO), and silver nanowires that make up a photovoltaic device. This combination means that the artificial skin can convert ultraviolet light into useful electricity, which can be used to sustainably power wearable electronics, according to a news release issued by Incheon National University.

The use of ZnO generates an electrical current that increases with temperature (pyrocurrent). This sensing platform also has inherent memory properties, meaning that the pyrocurrent is more or less amplified depending on previous exposure to extreme temperatures. This technology mimics some of the sensory memory mechanisms that human skin has that enables it to avoid harmful stimuli.

“Artificial skin could become an immediate solution for people with damaged skin sensors so that they can once again experience the natural environment around them with ease,” said Professor Kim, in the release.  "Our work paves the way for the combination of biosensing and built-in memory capabilities via a self-powered architecture, which could find uses in artificial thermoreceptor sensors, self-powered e-skin, artificial biomedical sensors, artificial sensing and memory, and thermal memory."

Professor Kim and his team have made their findings available in a paper entitled, “Transparent photovoltaic skin for artificial thermoreceptor and nociceptor memory,” which was published in Volume 91 of Nano Energy in January 2022.