This Transparent Flexible Circuit Fits on a Contact Lens

By Wesley Fenlon

Science inches closer to outfitting our bodies with tiny, near-invisible electronics.

Silicon-based circuitry is so passé. Who wants to look at a circuit embedded in silicon when there are bendable, transparent, micrometer-thick circuits to gawk at? Such a thing exists, as a group of Swiss researchers have shown in their research paper "Wafer-scale design of lightweight and transparent electronics that wraps around hairs." As a proof-of-concept, the researchers have embedded a tiny transparent circuit in a contact lens. The circuit sits just over the pupil. You might need a magnifying glass to get a good look.

Smithsonian Mag explains that the circuit embedded in a contact lens could help monitor intraocular pressure of those who suffer from glaucoma, but this is just an early implementation of the tiny circuit. In the future, the researchers hope to use it in other areas of biometric science, implanted in the body after surgery to track blood pressure or unobtrusively attached to the skin.

Photo credit: Giovanni A Salvatore via Smithsonian Mag.

The circuit's physical flexibility should make for wide-ranging implementations. The circuits "are printed on a one-micrometer thick layer of a substance called parylene" in a complex process, Smithsonian Mag writes. "To begin, the scientists deposit the parylene on vinyl polymer that provides support, then print the circuitry on top of the parylene. Afterward, the entire chip is placed in water, which dissolves the underlying polymer, leaving the ultra thin circuitry intact. The result is something that’s about one-sixtieth as thick as a human hair."

It's so thin, it can wrap around a human hair. Or a finger, in larger sizes. Now here's the bad news about this circuit's flexibility: It can't do everything by itself. It's a circuit, not a sensor or a battery, which means it needs to be paired with those things to read your blood pressure or serve any other biometric function. Before the circuitry is useful, it'll have to be paired with other similarly flexible and thin components.

That will take years. The good news, though, is those technologies are in the works, too. Remember that flexible battery we wrote about last year? Perhaps these two things are meant to be together. Converge faster, technology!