| dc.description.abstract | This study aims at fabricating micro-pin arrays on a glass substrate using the technique of laser-induced plasma assisted micromachining (LIPMM). The ablating
plasma is generated by irradiating laser light on two different target substrates, 304 stainless steel and graphite, respectively. Various surface morphologies of micro-pin arrays, obtained by different laser operating parameters and scan schemes, are examined and discussed. The influence of plasma intensity on the glass ablation and
the resulting surface morphology of the micro-pin array is investigated by varying the spacer’s thickness, the distance separating the glass from the target substrate.
In the first part of this study, we introduce the formation mechanism of micro-pin arrays and compare both surface morphologies of the glass and graphite target substrates at different scan schemes and scan times. We find that the surface morphology of graphite substrate shows a particular relationship with the glass surface profile. When the scan times is 5, the graphite substrate displays a 7 × 7 array as the scan path. As the scan times is increased to 50, a black hole at the center of the square of array is observed. It is because the convex pyramid structures on the glass behaving as focusing centers that converging laser light and ablating the square array centers.
The second part of this study focuses on the surface profile (pin height, pin width, array depth and the height difference from the original glass surface) using different
experiment parameters (scan times, power, the thickness of spacer, and target substrate). We find that the pin height, pin width, and array depth are increased with power and scan times. When the thickness of spacer is increased to 700 um, the pin height and array depth are directly proportional to the laser power, but both of them are smaller than that of 225 um thickness. Finally, if graphite plate is served as the target substrate, the pattern of micro-pin array is shallower. This is because the plasma formation threshold of the graphite plate is higher than that of stainless steel. | en_US |