A flexible new platform for high-performance electronics

September 28, 2017

MADISON, Wis. -- A team of University of Wisconsin-Madison engineers has created the most functional flexible transistor in the world -- and with it, a fast, simple and inexpensive fabrication process that's easily scalable to the commercial level.

It's an advance that could open the door to an increasingly interconnected world, enabling manufacturers to add "smart," wireless capabilities to any number of large or small products or objects -- like wearable sensors and computers for people and animals -- that curve, bend, stretch and move.

Transistors are ubiquitous building blocks of modern electronics. The UW-Madison group's advance is a twist on a two-decade-old industry standard: a BiCMOS (bipolar complementary metal oxide semiconductor) thin-film transistor, which combines two very different technologies -- and speed, high current and low power dissipation in the form of heat and wasted energy -- all on one surface.

As a result, these "mixed-signal" devices (with both analog and digital capabilities) deliver both brains and brawn and are the chip of choice for many of today's portable electronic devices, including cellphones.

"The industry standard is very good," says Zhenqiang (Jack) Ma, the Lynn H. Matthias Professor and Vilas Distinguished Achievement Professor in electrical and computer engineering at UW-Madison. "Now we can do the same things with our transistor -- but it can bend."

Ma is a world leader in high-frequency flexible electronics. He and his collaborators described their advance in the inaugural issue of the journal Flexible Electronics, published Sept. 27.

Making traditional BiCMOS flexible electronics is difficult, in part because the process takes several months and requires a multitude of delicate, high-temperature steps. Even a minor variation in temperature at any point could ruin all of the previous steps.

Ma and his collaborators fabricated their flexible electronics on a single-crystal silicon nanomembrane on a single bendable piece of plastic. The secret to their success is their unique process, which eliminates many steps and slashes both the time and cost of fabricating the transistors.

"In industry, they need to finish these in three months," he says. "We finished it in a week."

He says his group's much simpler high-temperature process can scale to industry-level production right away.

"The key is that parameters are important," he says. "One high-temperature step fixes everything -- like glue. Now, we have more powerful mixed-signal tools. Basically, the idea is for flexible electronics to expand with this. The platform is getting bigger."
His collaborators include Jung-Hun Seo of the University at Buffalo, State University of New York; Kan Zhang of UW-Madison; and Weidong Zhou of the University of Texas at Arlington.

This work was supported by the Air Force Office of Scientific Research (grant No. FA9550-09-1-0482).

Renee Meiller

University of Wisconsin-Madison

Related Transistor Articles from Brightsurf:

Transistor-integrated cooling for a more powerful chip
EPFL researchers have created a single chip that combines a transistor and micro-fluidic cooling system.

Study: Paper-thin gallium oxide transistor handles more than 8,000 volts
University at Buffalo electrical engineers created a gallium oxide-based transistor that can handle more than 8,000 volts.

Single-electron pumping in a ZnO single-nanobelt transistor
Diluted magnetic semiconductors (DMSs) have traditionally been employed to implement spin-based quantum computing and quantum information processing.

Black phosphorous tunnel field-effect transistor as an alternative ultra-low power switch?
Researchers have reported a black phosphorus transistor that can be used as an alternative ultra-low power switch.

A record-setting transistor
A transistor that could be the key to higher bandwidth wireless communications...while requiring less battery life.

Beyond Moore's Law: Taking transistor arrays into the third dimension
Silicon integrated circuits, which are used in computer processors, are approaching the maximum feasible density of transistors on a single chip -- at least, in two-dimensional arrays.

Researchers build transistor-like gate for quantum information processing -- with qudits
Purdue University researchers are among the first to build what could be a quantum version of a transistor -- with qudits.

Organic semiconductors: One transistor for all purposes
In mobiles, fridges, planes - transistors are everywhere. But they often operate only within a restricted current range.

Organic electronics: Scientists develop a high-performance unipolar n-type thin-film transistor
Researchers at Tokyo Institute of Technology (Tokyo Tech) report a unipolar n-type transistor with a world-leading electron mobility performance of up to 7.16 cm2 V-1 s-1.

Learning transistor mimics the brain
A new transistor based on organic materials has been developed by scientists at Linköping University.

Read More: Transistor News and Transistor Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.