Design Optimization of Fixed-Valve Micropumps for Miniature Cooling Systems

The piezoelectrically driven fixed-valve micropump may be an attractive choice for miniature liquid cooling systems due to its low-cost potential and simple fabrication. The thin, stackable design can be fabricated in many materials, including silicon, metal and plastic. Previous linear system modeling has been used to predict resonant behavior in terms of valve Reynolds number and used as a guideline for design, but can not yield predictions of pressure and flow, which depend on nonlinear fluid dynamic phenomena. In this study we report an extended model that incorporates the calculation of block-load pressure and no-load flow in a manner such that thousands of designs can be analyzed quickly. The results indicate that by calculating these two pump performance parameters over a design space of valve size and actuator stiffness, pump design is better able to match pump performance to system requirements. Experimental verification was performed using prototype pumps with interchangeable plastic and metal parts to demonstrate the approach for these two low cost materials.