Bendable nanoporous copper thin films with tunable thickness and pore features

Three dimensional nanoporous copper (NPC) films with tunable thickness ranging from ∼230 nm to ∼2.2 μm were fabricated by dealloying Cu-Zr-Al metallic glasses. The ductile-to-brittle transition behavior of the NPC was firstly explored. Moreover, by systematically investigating the influence of Cu content and dealloying temperature on nanoporosity, it was found that, as the Cu content increased, the pore size significantly decreased. In addition, decreasing the dealloying temperature could result in the formation of ultrafine nanoporous structure. Our current work provides bendable ultrathin NPC films with tunable nanoporosity, which is promising for functional applications in micro/nano electromechanical systems.