E-skin just got skinnier

The original news release was published by University of Tokyo.

Big news came a few days ago from the University of Tokyo, where researchers created ultrathin, ultraflexible protective layer, which was then used for creating air stable organic light-emitting diode (OLED). While OLED technology is already consumer available, the protective layer is the revolutionary part of this breakthrough. It enables the display to be really ultrathin.

So far, the attempts were failing, because very thin materials were not able to survive longer exposure to air. The thicker materials on the other hand were not flexible enough and hence impractical for development of technology like e-skin.

“What would the world be like if we had displays that could adhere to our bodies and even show our emotions or level of stress or unease? In addition to not having to carry a device with us at all times, they might enhance the way we interact with those around us or add a whole new dimension to how we communicate” Professor Takao Someya who was in charge of the research.

Images on top portray the light emiting polymer diode sensor together with organic photo detector, where the medical data is produced, bottom picture shows where the data is then displayed. Image courtesy of Someya Laboratory.

Thanks to the discovery made in this research, e-skin is much closer to reality. The newly developed protective skin is just 2 micrometers thick. It was created by switching layers of inorganic (Silicon Oxynitrite) and organic (Parylene) material. The skin is now more resistant to effects of oxygen and water vapors. Because of this, its lifetime was extended to multiple days, whereas the versions from previous experiments were functional only for couple hours. It was possible to attach electrodes to this material without damaging it, making it very practical for e-skin technology. The working prototype has sensors to monitor pulse rate and blood oxygen level.

In addition to this, the researchers designed special polymer light-emitting diodes (PLEDs) and organic photodetectors (OPDs), which together with indium tin oxide (ITO) electrodes made the whole system generate less heat and become six times more efficient compared to previous technologies. This makes it more convenient for a real life application. Health sector could be interested in this system, as it is able to portray real time medical information from sensors directly on patient’s skin. E-skin displays could become a direct competition or a replacement for sport watches, especially in sports where watches are just too impractical.