Grant: Discovery Grants Program - Individual

Jets of small abrasive particles propelled by compressed gases have been used for many years to modify engineering surfaces. One of the most interesting and important applications of abrasive jet technology is as a low cost and rapid micromachining technology for the fabrication of components used in microfluidics, microelectromechanical systems (MEMS), and opto electronics applications. Besides its low cost, the technology is attractive because it does not involve the use of harmful chemicals, and it allows for one pass fabrication of micro-features at different depths, something that is difficult with traditional wet etching techniques. The proposed research focuses on the investigation of two poorly understood aspects of abrasive jet micromachining (AJM): (i) The role that particle material, size and shape and target curvature have on machining precision and (ii) the development of models and techniques to use abrasive jets to machine three dimensional (3D) features. For the AJM of surfaces patterned with erosion resistant masks, smaller particles can arrive closer to the mask edge than larger ones. Also, as machined features such as micro-channels become deeper and narrower, only the smaller particles will strike the bottom. As a result, the particle size and shape distributions strongly affect the distribution of erosive potential. Modelling of these effects will allow for an optimization of the AJM of high aspect ratio microchannels and microholes. Due to its ability to directionally etch, AJM can be used to machine complex 3D features, using an inclined abrasive jet passed through a patterned erosion resistant mask. The development of a generally applicable model of this oblique blasting process will allow predictive abrasive jet micromachining of complex features that can be used in the next generation of microfluidic chips and MEMS devices.