Microscale wireless circuits may be definite game changers for wearable IoT

Original news release was published by University of Wisconsin-Madison, written by Renee Meiller.

Nowadays, wearable consumer devices are so widespread that it can be hard to get impressed by them, as useful as they are beyond their vanity features. Once in a while, however, a potential game changer comes in with a proof of concept that excites. These stretchy, crazy thin, but incredibly capable circuits may just be those game changers.

The reportedly world’s fastest stretchable, wearable integrated circuits were developed by a team of engineers from University of Wisconsin-Madison, led by Zhenqiang “Jack” Ma, the Lynn H. Matthias Professor in Engineering. This new system could bring the Internet of Things closer to complete ubiquity because at its thickness of 250 micrometers, you will be barely able to notice you even have a wearable device on you.

“We’ve found a way to integrate high-frequency active transistors into a useful circuit that can be wireless,” says Ma. “This is a platform. This opens the door to lots of new capabilities.”

What makes the new, stretchable integrated circuits so powerful is their unique structure, inspired by twisted-pair telephone cables. They contain, essentially, two ultra-tiny intertwining power transmission lines in repeating S-curves.

The serpentine shape of the circuits — formed in two layers with segmented metal blocks, like a 3-D puzzle — gives the transmission lines the ability to stretch without affecting their performance. It also helps shield the lines from outside interference and, at the same time, confine the electromagnetic waves flowing through them, almost completely eliminating current loss.

In an intensive care unit, epidermal electronic systems (electronics that adhere to the skin like temporary tattoos) could allow health care staff to monitor patients remotely and wirelessly, increasing patient comfort by decreasing the customary tangle of cables and wires.

The advance is a platform for manufacturers seeking to expand the capabilities and applications of wearable electronics — including those with biomedical applications — particularly as they strive to develop devices that take advantage of a new generation of wireless broadband technologies referred to as 5G. The new circuit design operates at wavelength sizes between a millimeter and a meter, and at frequencies in the .3 gigahertz to 300 gigahertz range. That falls directly in the 5G range, making this platform ready for the deployment of the next gen wireless communication.

Ma’s group has been developing what are known as transistor active devices for the past decade. This latest advance marries the researchers’ expertise in both high-frequency and flexible electronics.