Surface treatment comparison using atmospheric helium plasma jets with different frequencies and target objects

This paper details a plasma surface treatment feasibility study conducted for different driving frequencies of low frequency (LF, 50 kHz) and radio-frequency (RF, 13.56 MHz) sources by adding a target plate to a single pin electrode plasma jet system. The plasmas were generated in ambient air with a helium gas supply. The electrical characteristics of the plasmas were studied and compared for cases with and without a plane electrode. The LF plasma was more affected by the presence of the dielectric plate than was the RF plasma, showing a larger increase in its current. In addition, pork samples were treated to assess the electrical and thermal safety of plasma biomaterial surface treatments. The LF plasma conduction current and temperature during the pork treatment were 0.5 mA and 22 °C, and those of the RF plasma were 40 mA and 31 °C at maximum.