The flexible filter developed by the Rice lab of chemist James Tour may be of special interest to hospitals. According to the Centers for Disease Control and Prevention, patients have a 1-in-31 chance of acquiring a potentially antibiotic-resistant infection during hospitalization.

The device described in the American Chemical Society journal ACS Nano captures bacteria, fungi, spores, prions, endotoxins and other biological contaminants carried by droplets, aerosols and particulate matter.

The filter then prevents the microbes and other contaminants from proliferating by periodically heating up to 350 degrees Celsius (662 degrees Fahrenheit), enough to obliterate pathogens and their toxic byproducts. The filter requires little power, and heats and cools within seconds.

LIG is a conductive foam of pure, atomically thin carbon sheets synthesized through heating the surface of a common polyimide sheet with an industrial laser cutter. The process discovered by Tour’s lab in 2014 has led to a range of applications for electronics, triboelectric nanogenerators, composites, electrocatalysis and even art.

Adapting it for use as a filter meant laser-building graphene into both sides of the polyimide, leaving a fine, three-dimensional lattice of the polymer to reinforce the graphene foam. Laser-building at different temperatures resulted in a thick forest of graphene fibers with smaller, interconnected sheets underneath.

Like all pure graphene, the foam conducts electricity. When electrified, Joule heating raises the filter’s temperature above 300 C, enough to not only kill trapped pathogens but also to decompose toxic byproducts that can feed new microorganisms and activate the human immune system.