Stable, amphiphobic, and electrically conductive coating on flexible polyimide substrate

A flexible electrode material, with good surface amphiphobicity and mechanical and chemical stability, was fabricated herein using a simple process. A superhydrophilic nanopillar array with a high aspect ratio was formed on a flexible polyimide substrate by radio-frequency plasma etching using a sputtering system. A superhydrophobic and electrically conductive silver nanopillar array was constructed by sequentially depositing Ag thin films without breaking the vacuum. Good surface amphiphobicity was achieved by fluorination on the Ag nanopillar arrays using 1H,1H,2H,2H-perfluorodecanethiol (PFDT) solution. For the optimal sample, the contact angles for water and ethanol were approximately 166° and 120°, respectively. The water sliding angle and contact angle hysteresis were 3° and 1°, respectively, indicating the potential of the arrays to perform well in self-cleaning tests. Fingerprints were not observed after pressing the thumb on the surface, indicating the excellent anti-fingerprint property. Even after 10,000 bending cycles, the change in the electrical resistance was close to unity, and the surface amphiphobicity was well maintained, indicating the excellent mechanical durability. The superior electrical stability was exhibited even after immersion in different solutions such as water and acid. The superior performances render the Ag nanopillar array with PFDT a good candidate for use as a flexible electrode material.