Washable electronics? Water-repellent graphene circuits make it possible!

New graphene printing technology can produce electronic circuits that are low-cost, flexible, highly conductive and water repellent.

The nanotechnology "would lend enormous value to self-cleaning wearable/washable electronics that are resistant to stains, or ice and biofilm formation," according to a recent paper describing the discovery.

According to Jonathan Claussen, an Iowa State University assistant professor of mechanical engineering, an associate of the U.S. Department of Energy's Ames Laboratory, they’re taking low-cost, inkjet-printed graphene and tuning it with a laser to make functional materials.

The research group used inkjet printing technology to create electric circuits on flexible materials. In this case, the ink is flakes of graphene -- the wonder material can be a great conductor of electricity and heat, plus it's strong, stable and biocompatible.

The printed flakes, however, aren't highly conductive and have to be processed to remove non-conductive binders and weld the flakes together, boosting conductivity and making them useful for electronics or sensors.

Typically, post processing involves heat and chemicals, but here Claussen and his research group developed a rapid-pulse laser process that treats the graphene without damaging the printing surface -- even if it's paper.

Claussen further added that they’re micro-patterning the surface of the inkjet-printed graphene and the laser aligns the graphene flakes vertically like little pyramids stacking up, and that's what induces the hydrophobicity.

The energy density of the laser processing can be adjusted to tune the degree of hydrophobicity and conductivity of the printed graphene circuits. The technology could also have applications in flexible electronics, washable sensors in textiles, microfluidic technologies, drag reduction, de-icing, electrochemical sensors and technology that uses graphene structures and electrical simulation to produce stem cells for nerve regeneration.

The graphene printing, processing and tuning technology is turning out to be very useful. After all, "electronics are being incorporated into everything."