Minimising plasma irradiation area by micronozzle device towards single-cell treatment

A micro plasma-nozzle device has been fabricated for plasma treatment for a single cell. The micro plasma-nozzle device consists of throughhole and trench structures. The nozzle device was attached to a guide tube (O.D.: φ1.5 mm, I.D.: φ1 mm) of an atmospheric pressure microplasma. Once plasma gas was supplied into the guide tube, most of the plasma gas was exhausted through trench structures, whereas the remaining plasma was excited through the nozzle hole. The nozzle device with φ5 μm holes achieved minimum plasma irradiation onto a PDMS film. The plasma-modihed area was φ.4-5.6 μm, which was much smaller than the area size modified by direct plasma irradiation from the guide tube (φ3-4 mm). The plasma irradiation caused protrusions on the PDMS surface. The minimised plasma irradiation formed 170 nm-height-protrusion-structures on the PDMS surface. The plasma irradiation through the nozzle device was applied to an onion tissue using a nozzle device with φ10 mm holes. The plasma irradiation formed φ-15 μm holes in the onion cell membrane.