Shin-Yi Wu

Low-Temperature Atmospheric-Pressure-Plasma Jet for Thin-Film Deposition

A novel plasma system based on double-pipe method was generated for the development of an atmospheric-pressure-plasma jet (APPJ). This APPJ deposits homogeneous thin films without unfavorable contamination in plasma source. The experimentally measured gas-phase temperature of the argon APPJ maintained at RF electric power was around 40degC-80degC, indicating this APPJ to be a low-temperature plasma. This plasma system will provide a chamber less deposition for coating application.

Synthesis of Organosilicon Film on Polycarbonate by Means of Low-Temperature Atmospheric-Pressure Plasma Jet

Plasma-polymerized organosilicon films are deposited at room temperature by a novel double-pipe-type atmospheric-pressure plasma jet (APPJ), using hexamethyldisilazane (HMDSN) as precursor and argon (Ar) as carrier gas. The surface properties of the resulted plasma films are investigated as a function of radio-frequency plasma power and position from the plasma nozzle. The atmospheric-pressure plasma-polymerized films have been analyzed by static contact angle measurement, a Fourier transform infrared spectrometer, a UV-vis spectrometer, and atomic force microscopy. The ultrathin APPJ-polymerized films have been studied and correlated to chemical composition and surface morphology. UV-vis spectra have demonstrated the optical transparency of the APPJ polymerized films.

Low-Temperature Cyclonic Plasma Created at Atmospheric Pressure

Cyclonic atmospheric pressure plasma with low-temperature nature has been investigated. High-speed rotating nonthermal atmospheric plasma jets were utilized as RF plasma sources to provide the gas velocities required to generate the cyclonic gas flow patterns. It was shown that the plasma temperature could be controlled by operational parameters. The experimentally measured gas phase temperature was around 30degC-85degC, indicating that this cyclonic atmospheric pressure plasma can treat polymers without unfavorable thermal effects. This type of low-temperature atmospheric plasma can provide a novel technique for large-scale surface modification of heat-sensitive materials.

Static Water Contact Angle Analysis of Cyclonic Atmospheric Pressure Plasma-Activated Polycarbonate

Polycarbonate (PC) films were activated using cyclonic atmospheric pressure plasma. The experimentally measured gas phase temperature was from 30 to 95 °C, demonstrating that this cyclonic atmospheric pressure plasma can treat heat-sensitive polymeric materials at the low temperatures. The surface hydrophilicity changes of cyclonic atmospheric pressure plasma-treated PC films were determined by water contact angle analysis. The activation effects of plasma operational parameters including treatment time, plasma power, and distance of nozzle to substrate on the PC surface features were investigated. The glow feature and luminous plasma species in the cyclonic atmospheric pressure plasma were identified by optical emission spectroscopy (OES). Cyclonic atmospheric pressure plasma-activated PC films showed a significant decrease in water contact angle. In this investigation, we developed an innovative technique for chamberless polymeric surface activation by this atmospheric pressure plasma processing.

Degradation of Bacillus Subtilis by Cyclonic Atmospheric-Pressure Plasma

This paper investigates the sterilization effects of a low-temperature cyclonic atmospheric-pressure plasma. Bacillus subtilis was exposed to the cyclonic atmospheric-pressure plasma, and the degradation of the bacterial cell was thoroughly examined with scanning electron microscopy. It was found that cyclonic atmospheric-pressure plasma is effective in the destruction of the B. subtilis cells.