Scientists create new platform to drive Internet of Things

In an advance that could drive the Internet of Things, scientists have created the world's fastest stretchable, wearable integrated circuits. The development would lead to a much more densely connected, high-speed wireless planet.

The platform developed by researchers from the University of Wisconsin-Madison, would help manufacturers expand the capabilities and applications of wearable electronics - including those with biomedical applications especially as they strove to develop devices that took advantage of a new generation of wireless broadband technologies referred to as 5G.

In a press release, the University of Wisconsin said, With wavelength sizes between a millimeter and a meter, microwave radio frequencies are electromagnetic waves that use frequencies in the .3 gigahertz to 300 gigahertz range. That falls directly in the 5G range.

Led by Zhenqiang ''Jack'' Ma, the Lynn H Matthias professor in Engineering and Vilas Distinguished Achievement professor in electrical and computer engineering at UW–Madison, the researchers published details of these powerful, highly efficient integrated circuits today, 27 May, 2016, in the journal Advanced Functional Materials.

In mobile communications, the wide microwave radio frequencies of 5G networks will accommodate a growing number of cellphone users and notable increases in data speeds and coverage areas.

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.

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.

This serpentine shape - 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. Currently, the researchers' stretchable integrated circuits can operate at radio frequency levels up to 40 gigahertz.

The advance could allow health care staff to monitor patients remotely and wirelessly, increasing patient comfort by decreasing the customary tangle of cables and wires.

And, unlike other stretchable transmission lines, whose widths can approach 640 micrometers (or .64 millimeters), the researchers' new stretchable integrated circuits are just 25 micrometers (or .025 millimeters) thick.

That's tiny enough to be highly effective in epidermal electronic systems, among many other applications.

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.

''We've found a way to integrate high-frequency active transistors into a useful circuit that can be wireless,'' says Ma, whose work was supported by the Air Force Office of Scientific Research. ''This is a platform. This opens the door to lots of new capabilities.''

Other authors on the paper include Yei Hwan Jung, Juhwan Lee, Namki Cho, Sang June Cho, Huilong Zhang, Subin Lee, Tong June Kim and Shaoqin Gong of UW–Madison and Yijie Qiu of the University of Electronic Science and Technology of China.