Using the improved DSMC method to predict the reliability of micro-flow channels

• Main Authors: Ping Tang, Jian Yang, Jianjun Ye, Jinyang Zheng, Chikong Lam, Leong Wong, Yanbao Ma
• Format: Conference Proceeding
• Language: English
• Subjects: CFD analysis; DSMC; Finite element methods; Materials reliability; Micro-fluidics; Microchannel; Microfluidics; Microstructure; Monte Carlo methods; Parameter estimation; Prediction methods; Predictive models; Reliability; Stress
• DOI: 10.1109/NEMS.2009.5068594

Reliability of microfluidic designs is an extremely important issue that defines the range of applicability of micro-devices. The reliability design of micro-channels presents new complications that require extensions of today's method to incorporate reliable prediction methodologies. In this paper, using the improved direct simulation Monte Carlo, a prediction method was proposed for the reliability design of micro-flow channels. The direct simulation Monte Carlo method appears to be useful in micro-flow simulations because the corresponding Knudsen numbers are often beyond those that can be simulated by continuum approaches. Based on the assumption of certain pressure distributions with the second-order on the boundaries in the micro flow cells, the improved DSMC method was used to obtain the corresponding pressure and viscous forces of the micro-flow. For all boundaries of the microstructure interacting with the fluid experienced loads from the flow, the load was expressed as the sum of the corresponding pressure and viscous forces obtained from the DSMC method. Using the finite element method, the stress distribution and the deformation of the microstructure under the loads can then be given. Considering failure criteria of the material and structure, the reliability parameters were further estimated and analyzed. In order to demonstrate the effects of the method in optimizing the design of microfluidic devices, the performance and reliability predictions are made for a microchannel under backward-facing flows. The results show that the method is necessary and effective to predict weak spots of micro devices and prevent the extreme deformation in design of microchannels.