Pulsating flow triggered by the laser induced phase change in microchannels with sawtooth-shaped baffles

Abstract

The study on cells in vitro usually encounters the signals with oscillatory or periodic temporal profiles, which requires the pulsating flow control. Aiming at this target, a novel approach to generate the pulsating waveform of fluid flow by the photothermally induced phase change in the microchannel with the sawtooth-shaped baffles was developed in this work. It was demonstrated that the periodical immobilization-motion-immobilization flow behavior was formed by the combined photothermally induced interfacial behaviors and the in-channel baffle structures, which successfully generated stable oscillating flow with good response. To further explore the pulsating flow behaviors, effects of the baffle design and input laser power were also investigated. It was shown that increasing the baffle width and interval distance between them could yield large pulse peak flow rate but low frequency, while both the pulse peak flow rate and frequency increased with the input laser power. These results indicate that via the change of the baffle design parameters and laser power, the pulse flow waveform can be well controlled for the in vitro cellular studies.