An ultrathin electronic skin (e-skin) that can measure oxygen levels when stuck to the body has been developed by Japanese scientists. The e-skin is developed using flexible electronics that can be worn as a second skin for biomedical applications.
The e-skin can be used by athletes to view their heart rates, sugar levels, and work rate. This helps provide doctors with continuous vital signs without the need for repeatedly attaching and removing medical equipment. While others could use e-skin to monitor their body health metrics.
‘The ultrathin, ultra-flexible electronic skin can be used to monitor heart rates, sugar levels, and measure blood oxygen levels.
"Such is the promise of ultra-thin, flexible, and non-constraining skin-level electronics," said Takao Someya, head of the research group seeking to develop e-skin at the University of Tokyo's Graduate School of Engineering.
The film is composed of alternating layers of a ceramic material (silicon oxynitrite) and Parylene (a polymer coating). The protective film prevented the passage of oxygen and water vapor in the air, extending their lifetime from a few hours seen in prior research to several days. The overall thickness of the e-skin is 3 microns (3 millionths of a meter), which is ten times thinner than our skin.
The scientists attached transparent indium tin oxide (ITO) electrodes to an ultrathin substrate without damaging it, making the e-skin display possible. They created polymer light-emitting diodes (PLEDs) and organic photodetectors (OPDs), using new protective layer and ITO electrodes.
The PLEDs were three micrometers thick and over six times more efficient than previously reported ultrathin PLEDs. Researchers combined red and green PLEDs with a photodetector to demonstrate a blood oxygen sensor.
"The device unobtrusively measures the oxygen concentration of blood when laminated on a finger," said lead researcher Tomoyuki Yokota and colleagues.
"Ultimately, flexible organic optical sensors may be directly laminated on organs to monitor the blood oxygen level during and after surgery," he added.