As described in a recently published paper in Nano Letters, UC Davis Adjunct Professor Kai Liu and collaborators have demonstrated light weight nanowire-based metal foam filters that are highly efficient, durable, reusable, and recyclable, particularly for deep submicron airborne particulates. They combine extremely large surface areas with excellent mechanical properties. This is relevant for combating viruses like COVID-19, as well as air pollution.  The research was supported in part by the Tom and Ginny Cahill Fund for Environmental Physics (UC Davis Professor Emeritus Tom Cahill).