Fig. 3.

a Optical image of a column of microplasma jets emerging from the array device (top) and impinging on a PVC biofilm coupon which was located 4.0 mm from the exit face of the array. The He gas flow was maintained at 0.25 L/min/microchannel and the red, horizontal region indicates the surface of the coupon; b–e (in cross-section) of a biofilm, prior to and following exposure to the He microplasma arrays for three time periods (t): 5, 15, and 20 min. For t = 20 min., no biofilm is detectable to within experimental uncertainty. The solid red line denotes the boundary between the biofilm and the surface of the PVC coupon