Development of wire spraying for direct micro-patterning via an atmospheric-pressure UHF inductively coupled microplasma jet

We developed wire spraying for direct micro-patterning via an atmospheric-pressure inductively coupled microplasma (AP-ICMP) jet of 20–50 μm in diameter. A 50–100-μm diameter metal wire inserted in the nozzle was melted or evaporated efficiently at a few tens of watts by inductive heating as well as heat conduction from the microplasma and the resulting atomized droplets were jetted out with plasma-gas flowing. Most of the sprayed grains were oxidized during the processing and a deposit composed of metal oxide grains built up locally on the polymeric substrate. Because of the low heat flux due to small plasma size and low energy supply, this spraying is useful for deposition on low melting-point polymeric substrates. Additionally, the feasibility of line drawing with micron-width was demonstrated by linear translation of the substrate.