It is intuitive that round microchannels would work better than square ones for a bubble-driven micropump, thank to elimination of leak flows from the corners. However, the boldest guess on the potential improvement may never exceed tens of percentage. During the last two years, graduate student, Ryan Lemmens, has spared numerous amount of his sleeping time in the lab to accurately characterize the effect. Astonishingly, he found that the maximum output flow power of a valve-less bubble-driven micropump can be improved to 3.6-4.6 times, by simply swapping the commonly used square/rectangular microchannels to round ones. Dennis Desheng Meng, the faculty advisor of Ryan and a co-author of the paper explained that the research may lead to new means for significant power saving and performance improvement in microfluidic devices, such as micro total analysis systems for biomedical analysis. The results have been scheduled to be published this September on Sensors and Actuators.