Temperature Dependence of Inertial Pumping in Microchannels

Inertial pumping is a promising new method of moving fluids through microchannels but many its properties remain unexplored. In this work, inertial flow rates are investigated for different channel lengths, operating temperatures, and resistor pulse energies. Flow in closed channels visualized by adding fluorescent tracer beads to the test fluid (pure water). A robust methodology extracting from high-resolution video recordings developed. found scale inversely with length. The observed dependence explained based on simple phenomenological "kick" model pumping. also fitted more fundamental one-dimensional which intrinsic drive bubble strength extracted. measured vary strongly temperature. For well-developed bubbles, at T = 70C about 12x higher than 30C. Three separate effects contribute increasing high temperatures: (i) lower viscosity fluid, (ii) stronger bubble, (iii) mechanical efficiency pump, i.e., better conversion unidirectional post-collapse kick. Relative contributions three quantified. energy exhibits clear saturation behavior. model. end, complete predictive length-temperature-energy constructed. strong temperature should be considered when designing microfluidic workflows. It highlights need integrated flowmeters that could stabilize complex patterns via sensory feedback.