Invisible, stretchable circuits to shape next-gen tech

February 12, 2018, Carnegie Mellon University Mechanical Engineering
The displays and touchscreens used in next-generation technologies will require transparent conductors that are soft, elastic, and highly stretchable. Credit: Soft Materials Laboratory, Carnegie Mellon University

Electrically conductive films that are optically transparent have a central role in a wide range of electronics applications, from touch screens and video displays to photovoltaics. These conductors function as invisible electrodes for circuit wiring, touch sensing, or electrical charge collection and are typically composed of transparent conductive oxides. But, they have a weakness.

Most are mechanically stiff. Stretching the inelastic material causes it to break apart and lose electrical functionality. This inability to support strain greatly limits the role of these existing for emerging applications in wearable computing, soft bioelectronics, and biologically-inspired robotics. The displays and touchscreens used in these next-generation technologies will require transparent conductors that are soft, elastic, and highly stretchable.

Carnegie Mellon University's Associate Professor of Mechanical Engineering Carmel Majidi and his research team have developed conductive thin-films that have the unique combination of properties needed for these next-generation technologies: , visual imperceptibility, low mechanical stiffness, and high elasticity.

Using a laser-based microfabrication technique, the team achieved these properties by coating the surface of a thin rubber film with a fine grid of metal (a eutectic alloy of gallium and indium, EGaIn) that is liquid at room temperature.

To demonstrate the usefullness of the material, the team created a system that monitors air quality and provides visual feedback on pollutant concentration using an electronic contact lens display. Credit: Soft Materials Laboratory, Carnegie Mellon University

The findings were published in Advanced Materials in a paper titled "Visually Imperceptible Liquid Metal Circuits for Transparent, Stretchable Electronics with Direct Laser Writing" by Chenfeng Pan, Kitty Kumar, Jianzhao Li, Eric J. Markvicka, Peter R. Herman, Carmel Majidi.

Majidi heads the Integrated Soft Materials Laboratory at Carnegie Mellon University.

Explore further: Researchers engineer 'thubber,' a stretchable rubber that packs a thermal conductive punch

More information: "Visually Imperceptible Liquid Metal Circuits for Transparent, Stretchable Electronics with Direct Laser Writing," Advanced Materials, DOI: 10.1002/adma.201706937

Related Stories

Fluidic transistor ushers the age of liquid computers

November 3, 2017

Transistors, those tiny electrical switches that process signals and data, are the brain power behind every electronic device – from laptops and smartphones to your digital thermostat. As they continue to shrink in size, ...

Recommended for you

Chemists characterize the fatal fungus among us

July 19, 2018

Life-threatening fungal infections affect more than two million people worldwide. Effective antifungal medications are very limited. Until now, one of the major challenges is that the fungal cell wall is poorly understood, ...

Infrared sensor as new method for drug discovery

July 19, 2018

Using an infrared sensor, biophysicists at Ruhr-Universität Bochum (RUB) have succeeded in analysing quickly and easily which active agents affect the structure of proteins and how long that effect lasts. Thus, Prof Dr. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.