On-Chip AC Electrothermal Pump for Pulsatile Perfusion

Microphysiological systems (MPSs) have emerged as promising platforms for drug discovery and in vitro pharmacological testing. MPSs aid to reproduce physiologically relevant microenvironments, in which controlled perfusion can play important role. In this study, an on-chip AC electrothermal (ACET) pump was developed for pulsatile perfusion in microfluidic cell culture systems. The proposed pump generates fluid motion through the interaction between an applied electric field and temperature-dependent gradients in the electrical properties of the fluid. Pulsatile perfusion was produced by periodic application of an AC voltage to the electrode array, and the pulsation cycle could be controlled electrically. The maximum flow velocity increased with the applied AC voltage, demonstrating tunable flow generation by the ACET pump. To evaluate the applicability of the developed system to cell culture, human mesenchymal stem cells (hMSCs) were cultured under pulsatile perfusion conditions for five days. The results showed that osteogenic differentiation under pulsatile perfusion was higher than that under static culture conditions. These findings demonstrate the potential of the proposed on-chip ACET pump as a simple and effective platform for generating physiologically relevant pulsatile perfusion in microphysiological systems.