Development of multi-hole atmospheric pressure plasma jet for seed treatment

Abstract

The purpose of this research is to develop the multihole atmospheric pressure plasma jet (APPJ) for improving seed germination and growth. In this research, SolidWorks 2016 was used to design gas flow simulation inside the plasma source. The simulated results show that gas velocity at nozzle is uniform. As a result, there are the argon plasma beam come out every hole and no arcing. The APPJ was connected to the x-y-z scanner for controlling the plasma beam passing thoroughly with the seed. The length of the plasma beam is around 1 cm. The argon flow rates of 200 250 300 350 L/h were used to evaluate the optimum condition for stable discharge. It founds that the AC power of 893 W and a frequency of 52 kHz with the argon flow rate of 250 L/h is the suitable condition. The mung bean seed was used to study the effect of plasma treatment. The experimental results show that the treated and untreated seed have different seed growth. The treated seed gives a higher growth rate than the control around 18%. This is due to the effect of oxygen nitrogen and humid radicals in plasma which can increase the surface free energy of seed coat. As a result, the treated seed can absorb higher oxygen and moisture from the environmental.