A team of researchers from the University of Tokyo has created an ultrathin, ultraflexible protective layer. The unique device was used to create an air-stable, organic light emitting diode (OLED) display, which could be used to create e-skins that monitor blood oxygen and heart rate.
Researchers are working tirelessly to create electronic devices that can be integrated with the human body in order to enhance body function in medical applications, and the new study brings scientists closer to this goal.
In order to create functional e-skin, scientists must create technology that is thin and flexible in order to minimize impact on the areas that they attach to. Until now, most glass or plastic devices have possessed limited flexibility, whereas their organic counterparts have lacked the stability needed to survive in air.
In the new study, the team created a high quality protective film measuring less than two micrometers thick, allowing for the production of ultrathin, ultraflexible and high performance wearable e-skins.
The material is made from alternating layers of silicon oxynitrite, which is inorganic, and parylene, which is organic. This protective layer prevents the passage of oxygen and water vapor in the air, allowing for a longevity of several days, a big improvement over the short-lived devices in previous projects that lasted just a few days.
In combination with the protective layer, the team used transparent indium tin oxide (ITO) electrodes to create polymer light-emitting diodes (PLEDs) and organic photodetectors (OPDs) thin enough to be attached to the skin while also having a level of flexibility that allows it to crumble and stretch with the skin without being damaged.
The team demonstrated the potential of their OLED device by creating an e-skin that monitors blood oxygen.
"The advent of mobile phones has changed the way we communicate," said Takao Someya, a professor at the University of Tokyo and senior author of the study. "While these communication tools are getting smaller and smaller, they are still discrete devices that we have to carry with us."
"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?" he added. "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."
The findings were published in the April 15 issue of the journal Science Advances.
