Micro-scale fluid flows: The application of acoustic streaming to biomedical research Seminar

Shear stresses generated by haemodynamic flow and additional biological fluid flows play a vital role in the regulation of certain cellular processes. The continuation of research into the effects of shear stress requires a reliable method for applying shear stress to cells in vitro. Within the presentation I will discuss my research into the use of stable cavitation microstreaming flows for mechanically stressing cells. The streaming flows are generated around Expancel micro-bubbles by an acoustic standing wave setup in a purpose built microfluidic device. The flow is characterized by µPIV (micro particle image velocimetry) and used to mechanically stress H9C2 cardiomyocytes. The Expancel are fixed to the bottom internal surface of the devices 200 µm tall fluid chamber and cells are adhered to the top internal surface. With this setup it was demonstrated that the flow speed of cavitation microstreaming possessed a good degree of repeatability. It was also demonstrated that H9C2 cardiomyocytes could be killed by microstreaming at a separation distance of multiple microbubble diameters from the Expancel. Moreover, reasonably repeatable decreases in cell viability were achieved.