Capillary-based microsystems are inexpensive and easy to fabricate because they do not need any additional actuation mechanisms. Typical microsystems like micropumps and syringes need flow actuation rendering them bulky and not portable. Recent research at University at Buffalo has investigated a simple solution for moving fluid in micro-devices using capillary flow actuation. The work uses FLOW-3D to simulate the spontaneous capillary flow in a modified V-groove channel. The narrow V-groove geometry (left) provides a good solution because high viscosity fluids like whole blood can also be moved through it. The tip of the groove facilitates the spontaneous capillary flow and the parallel plates ensure sufficient amount of blood transport.
The research uses FLOW-3D to estimate the flow velocity of the fluid head in the channel and progression of liquid front. The results are compared with experimental and analytical (simplified) results. The plots below show the comparison of numerical, experimental and analytical results. FLOW-3D results are in excellent agreement with the experimental results.
FLOW-3D results in red circles at the mid flow height, experimental results in green dots recorded at the medium fluid height, analytical results in green dashes
Animation of the results post-processed in FlowSight.
J. Berthiera, K.A. Brakke, E.P. Furlani, I.H. Karampelas, V. Pohera, D. Gosselin, M. Cubizolles, P. Pouteau, Whole blood spontaneous capillary flow in narrow V-groove microchannels, Sensors and Actuators B: Chemical, 2014