Synthesis of Cu Nanowires by Template Electrodeposition and Their Application in Pressure Sensors

Electrodeposition of Cu within a porous anodic aluminum oxide template was used to synthesize Cu nanowires. Current density and deposition time had an influence on the growth mechanism of the nanowires. The suitable current density for nanowires growth was 15 mA/cm², which could not only obtain high quality but also ensured deposition efficiency. The diameter of the Cu nanowires was about 200 nm, being consistent with the template pore size, while the length of the nanowires had a linear growth rate of approximately 1.97 μm/min. Nanowires of different lengths could be obtained by controlling the deposition time. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to reveal the Cu nanowires’ crystal structure and morphology. An individual nanowire was a single crystal, and the uniformity of the nanowires could be kept after removal from the template. The nanowires were impregnated in a sponge skeleton and put on to interdigitated electrodes, covered by a polydimethylsiloxane film to make a pressure sensor. After 3 times dipping into the sponge, the pressure sensor had an appropriate content of nanowires, which could be deformed to make more Cu nanowires contacting with each other between different layers and the interdigital electrode. As a result, the pressure sensor worked successfully with more conductive pathways.