A breakthrough in electronics: a revolutionary electrochemical transistor has been created

A multidisciplinary research team at Northwestern University has created a revolutionary transistor that is expected to be optimal for bioelectronics that is high-performance, lightweight and flexible. The new electrochemical transistor is compatible with both blood and water and has the ability to amplify important signals, making it very useful for biomedical sensing. This transistor could enable the development of portable devices that can perform in situ signal processing directly at the interface of a biological device. Some potential applications include monitoring heart rate and blood sodium and potassium levels, as well as eye movement monitoring to study sleep disorders.

“All modern electronics use transistors that quickly switch current on and off,” said study co-author Tobin J. Marks. “Here, we use chemistry to improve the transition. Our electrochemical transistor takes performance to a whole new level. You have all the features of a conventional transistor, but with a small footprint that allows for much higher conductivity (a measure of the gain it can provide), ultra-stable cyclic switching characteristics, high-density integration. you have the footprint and easy, inexpensive production.”

Marks is a world leader in materials science and organic electronics. Vladimir N. Ipatiev is Professor of Catalytic Chemistry at the Weinberg College of Arts and Sciences and Professor of Materials Science and Engineering and Chemical and Biological Engineering at the McCormick School of Engineering.

The vertical electrochemical transistor is based on a new type of electronic polymer and has a vertical rather than planar architecture. It conducts both electricity and ions and is stable in air. The development and synthesis of new materials, as well as the manufacture and characterization of the transistor, required the combined expertise of chemists, materials scientists, and biomedical engineers.

Marks led the research team with Antonio Facchetti, Weinberg Professor of Chemistry; Wei Huang, currently a professor at China University of Electronic Science and Technology; and Jonathan Rivney, professor of biomedical engineering at the McCormick School.

“This exciting new type of transistor allows us to speak the language of both biological systems that communicate using ion signals and electronic systems that communicate with electrons,” Rivnai said. Said. “The ability of transistors to work very efficiently as ‘mixed conductors’ makes them attractive for bioelectronic diagnostics and therapy.”

This work and an accompanying News&Views article detailing an efficient electrochemical transistor were recently published in the journal. Nature.

“Because of their vertical nature, our electrochemical transistors can be stacked on top of each other,” Facchetti said. Said. “In this way, we can create very dense electrochemical complementary circuits that are impossible with conventional planar electrochemical transistors.”

To build more reliable and powerful electronic circuits, two types of transistors are needed: p-type transistors, which carry positive charges, and n-type transistors, which carry negative charges. Such chains are called complements. One problem researchers have faced in the past is that n-type transistors are difficult to make and are often unstable. This is the first study to show the same and very high performance electrochemical transistors for both types of (p+n) electrochemical transistors. This led to the fabrication of very efficient electrochemical complementary circuits.