A Multi-resonances Valveless Micropump with High Fluid Transportation Efficiency

Valveless pumping[1] is an ideal and biomimetic way of fluid transportation due to its simplicity and absence of moving elements which may cause fatigue problems. However, the issue of low efficiency makes against many microfluidic applications. In this research, the concept of multiple resonances was proposed to deal with the problem. The elastic chambers of intendedly-designed stiffness were equipped at inlet/outlet of valveless micropump. The second resonance is successfully induced for the enhancement of efficiency of fluid transportation by the interaction of fluid and structure with elastic boundary. The experiments showed that the size of elastic chamber had great effects on the operating frequency range and net flow rate. As Rb/Ra＝1.2 (Ra: radius of actuating chamber; Rb: radius of and inlet/outlet chamber), the maximum net flow rate is 15 times larger than the model of Rb/Ra＝0.12. Besides, a theoretical model relied on “Electric-Hydraulic-Analogy”[2] was proposed to effectively predict the dynamic behavior of the system. In conclusion, the novel concept of multiple resonances greatly enhances the applicability of valveless pumping, and the characteristic of multi-resonances micropump can be instantly and precisely estimated via the proposed model.