On-chip microfluidic perfusion for the introduction of tiny volume samples by utilizing spatiotemporal vortices generations.

Abstract

Perfusion cell culture is a significant technique for long-term culture by continuously exchanging media. Remarkably, microfluidic perfusion provides the advantages such as stable environment, low sample consumption and observability in microscope, which allows the observation of cell-cell communications. However, it is challenging to introduce/obtain the tiny samples into/from perfusion systems due to the use of large-sized chamber for culture medium placed outside. Here, we propose on-chip perfusion system by utilizing the piezo-driven membrane pump. In this method, we employ the asymmetric flow resistors which behave like diode by generating different vortices to flow direction leading direction-dependent flow resistances. This component can rectify the oscillatory flow of the membrane pump, and thus we can generate perfusion in microfluidic circuit. Using the method, we introduced the tiny samples of <100 μl and generated perfusion. These results indicate that our method can manipulate the tiny samples like floating cell to monitor cell-cell communications.