A self-powered pump based on gas-dissolved-in-liquid phenomenon to generate both negative and positive driving pressures

Abstract

A portable, self-powered multifunctional pump plays an important role in propelling microfluidic devices used in resource-limited applications, such as easily operated low-cost devices in field applications and simplified experiment setups in college laboratories. In particularly, a self-powered pumping device that can provide both positive and negative driving pressures with large driving force is highly desired. In this paper, we present a novel self-powered microfluidic pump based on the negative pressure generated by gas dissolution in liquid. Based on a pressure transformation mechanism, this pump can supply not only the negative pressure but also the positive one. The maximum pumping volume is around 15 mL and the flow rate can be regulated from around 0.1 mL/min to 0.6 mL/min by altering the flowing resistance. The pumping power is generated from the carbon dioxide dissolution in the sodium hydroxide solution. Then the generated negative pressure is linked to the pressure transformation mechanism which transfers the pressure into negative pressure or positive pressure. As a demonstration of its high driving pressure, the proposed self-powered pump has been successfully applied in the droplet generation. Such high driving capacity and flexibility of the presented self-powered pump shows its potentials to be a new type of passive pumps with wide applications in microfluidics.