High-speed Fabrication of Micro-channels using Line-based Laser Induced Plasma Micromachining (L-LIPMM)

Abstract

Micro-texturing of surfaces has various applications that often involve texturing over large (macro-scale) areas with high precision and resolution. This demands scalability and speed of texturing while retaining feature sizes on the order of a few ?m. Moreover, micro-channels are a versatile micro-feature that are often used in microfluidic devices and can be arrayed or joined to form patterns and free-form geometries. We present a technique to fabricate micro-channels on surfaces with high-speed and by using a multi-materials process, namely Laser Induced Plasma Micromachining (LIPMM). The process has the potential to machine metals, ceramics, polymers and other transparent, brittle and hard-to-machine materials. The presented technique uses an optical system to modify the laser spot into the shape of a line, to fabricate micro-channels directly without scanning as in the case of a regular circular spot. The process schematics are shown, and micro-machining experiments on polished Aluminum are discussed. Moreover, it is shown that the depth and width of the channels may be varied by changing the process parameters like the pulse energy, pulse frequency and number of exposures.