Low-Power Laser Processing-Based Approach to Plasma Lithography for Cell Micropatterning

Abstract

Plasma lithography is a technique to space-selectively create hydrophilic surfaces on silicone materials with oxygen plasma treatment. Cells can thus be micropatterned within the modified surfaces, allowing for artificially controlling the geometry of individual cell colonies. Conventional plasma lithography employs a photolithographically microfabricated mask with which the pattern geometry is determined. However, fast on-demand design change to the micropattern may be limited due to the time and cost associated with the sophisticated photolithographic fabrication. Here we attempted to microfabricate a mask for plasma lithography in a novel, quick, low-cost manner. An infrared absorption film was processed using a low-power Nd:YAG laser on an optical microscope to produce a mask of arbitrary pattern geometries. Our experiments indicate that plasma-shielding masks with various geometries are promptly obtained at a spatial resolution of several tens of microns with a laser power of below 200 mW. We demonstrate that cells are indeed micropatterned on functionalized silicone substrates so as to conform to the geometry of the laser-processed mask, thus suggesting the potential of this technique as a low-cost, fast on-demand means for cell micropatterning.