Engineers at North Carolina State University have created an ultra-thin, stretchable, and breathable electronic fabric for wearable projects — and, to demonstrate its capabilities, have turned it into a controller for Tetris.
“The gas permeability is the big advance over earlier stretchable electronics," claims Professor Yong Zhu, co-corresponding author of the paper detailing the new material. "But the method we used for creating the material is also important because it's a simple process that would be easy to scale up."
The process: The "breath figure method," which produces a stretchable polymer film covered in evenly-distributed holes. This film is then dipped into a solution of silver nanowires, then heat-pressed to seal the nanowires in place — creating a material just a few micrometres thick and breathable, yet suitable for use in wearable electronics projects.
"The resulting film shows an excellent combination of electric conductivity, optical transmittance and water-vapor permeability," claims Zhu. And because the silver nanowires are embedded just below the surface of the polymer, the material also exhibits excellent stability in the presence of sweat and after long-term wear."
To prove the concept, the team built two implementations. The first targeted healthcare use, putting dry electrophysiologic sensors for electrocardiography (ECG) and electromyography (EMG) measurement against the wearer's skin, with what Zhu claims was a signal quality "on par with commercially-available electrodes."
The second prototype, meanwhile, was a sleeve with an integrated touch-sensitive human-machine interface — used to great effect as a controller for video games, including classic block-sorting title Tetris.
The team's work has been published under closed-access terms in the journal ACS Nano under closed-access terms.