Organic optoelectronics ‘can be used as cheap medical sensors’

A new innovation in organic electronics could pave the way for cheap wearable sensors that can measure oxygen levels in the blood.

Engineers from the University of California, Berkeley have created an organic optoelectronic sensor that utilises red and green organic light-emitting diodes and photodiodes to measure arterial oxygen saturation and heart rate as accurately as conventional, silicon-based pulse oximeters.

Because of its carbon-based design, the device that could ultimately be thin, cheap and flexible enough to be applied like a plaster and discarded just as easily once they have been used and contaminated.

Research leader Ana Arias, an associate professor of electrical engineering and computer sciences at UC Berkeley, said: "We showed that if you take measurements with different wavelengths, it works, and if you use unconventional semiconductors, it works. Because organic electronics are flexible, they can easily conform to the body."

Traditional pulse oximeters use rigid conventional electronics and are usually fixed to the fingers or earlobes. Devices of this kind are used to track abnormally low levels of oxygen in the blood, a condition known as hypoxaemia.