Semipermanent Copper Nanowire Network with an Oxidation‐Proof Encapsulation Layer

Copper nanowires (Cu NWs) have gained attention as an alternative to noble metal nanowires due to their affordable price, but their susceptibility to rapid oxidization in ambient conditions has remained a critical limitation for their practical usage. Many studies have been conducted to address this disadvantage but have been successful only in terms of oxidation prevention at certain temperatures, leaving the matter of oxidation at high temperatures unresolved. In this article, a simple encapsulation structure made of a polyimide and SiOx thin film is presented that effectively prevents the penetration of oxygen and moisture into the Cu NW network. This structure, furthermore, boasts excellent stability at high temperature (≈350 °C) and in underwater, acidic chemical, and abrasive conditions. A simple encapsulation structure made with polyimide and SiOx thin film is proposed to prevent the oxidation of a Cu NW network. Such a network possesses excellent high‐temperature stability (≈350 °C) and superior performance underwater, in acidic chemicals, and abrasive conditions, which are largely avoided in previous studies, and it can be used as a flexible microheater.