Abstract
This work reports numerical and experimental investigations of a microfluidic hanging droplet platform, in which hanging drops (HDs) are generated automatically through openings at the bottom of a microfluidic channel for sustained three-dimensional (3D) cell culture. The simulation approach is based on the solution of the free surface equilibrium problem by the finite element method. In contrast to analytical solutions, it provides solutions to the critical advancing angle when the meniscus deforms due to an external driving pressure and proceeds on the wall of an expanding channel. Microfluidic HD systems have been fabricated in polydimethyl-siloxane (PDMS) by using soft lithography and PDMS membrane transferring techniques for testing the burst pressure. However, we found the discrepancy of the burst pressure between experiment results and numerical predictions, and it was due to the change of PDMS surface property. Thus, we had changed the contact angle of PDMS in simulation boundary conditions and found the trend of simulation results matched the experimental investigations.