Design and characterization of a micro single bubble actuator

A novel micro bubble actuator of specially designed micro heater (10/spl times/3 /spl mu/m/sup 2/) and single bubble system was fabricated and tested in DI water and two common DNA buffers (20 mM Tris-HC1 and 1X TAE). Under pulse heating, this actuator can generate highly localized homogeneous boiling and produces single bubbles periodically. Due to the asymmetry cycle of the bubble growth and collapse periods, the flow field can be effectively perturbed. This unique characteristic can be used to promote such actions as mixing in micro-bio-analytical systems. The thermal and hydrodynamic characteristics of the perturbed flow generated by the bubble actuator are investigated in this paper.