Prediction of erosion volume of PDMS by cryogenic micro-abrasive jet machining based on dimensional analysis method and experimental verification

Abstract

The polymer polydimethylsiloxane (PDMS) is used widely in microfluidic chips. At room temperature, when PDMS is machined by micro-abrasive jet machining (MAJM), its high elasticity means that it often suffers from processing defects such as abrasive embedding and a surface deterioration layer. Cryogenic micro-abrasive jet machining (CMAJM) based on the glass transition has been proposed, but a model for predicting the volume of material removed is yet to be established. In this study, orthogonal experiments are used to investigate how different processing parameters influence the material removal volume. The results show that the material removal volume is largest when the jet pressure is 0.6 MPa, the erosion angle is 60°, the erosion distance is 3.5 mm, and the scanning speed is 0.2 mm/s. A model is established to predict the material removal volume during the CMAJM of PDMS, and single-factor experiments are used to assess the model qualitatively. The results show that the model offers good predictions of how the material removal volume changes with the scanning speed and jet pressure.