Dynamic analysis of the demolding process for PDMS microstructures with high aspect ratio

This study aims to investigate several peel demolding schemes through numerical simulations for demolding of the PDMS film with high aspect ratio microstructures. Motivated by the need to improve the yield rate of our first generation, rotating arm based peel demolding system, numerical models based on the explicit dynamic finite element method are developed in order to identify a minimum stress design of the process which can minimize the maximum stress of microstructures during demolding. A scale-up approach is proposed to reduce computational time for the micro-scale problems. The experimental tests are also carried out to verify the findings from numerical simulations. From this study, the roller based demolding system is identified as the optimal scheme in our analysis cases and is developed as our next generation automatic demolding system (the maximum pillar stress can reduce 20% comparing to the rotating arm scheme).