Design and manufacturing of a piezoelectric traveling-wave pumping device

In this article, we present the design and construction of a micropump exhibiting a nontraditional pumping principle whose design is achievable at very low scales. The operation is based on the action of a mechanical traveling wave deforming the bottom wall of a flexible channel containing a fluid. The paper treats for the first time the influence of the traveling wave parameters on the performance of the pump with the help of finite element simulations. The results obtained from the simulation are subsequently used for the dimensioning of the linear ultrasonic traveling wave actuator that drives the device. Finally, a very simple channel-reservoirs structure was conceived to test the device. At this point, several measurements of flow rate and back pressure were carried out to estimate the performance of the prototype for different values of wave amplitude. The article finishes with a comparison between the numerical and experimental results and a brief section of discussion and conclusions.

I. Introduction

During the last two decades, the use of micropumps has reached many domains of science and technology. A huge diversity of designs, materials, and operating and actuation principles can be found in industry and the scientific literature. In spite of this significant variety, micropumps can always be identified as mechanical or nonmechanical devices [1]. Within the mechanical family, which is composed of devices requiring moving parts to function, actuation principles such as electrostatic [2], piezoelectric [3], electromagnetic [4], thermo-pneumatic [5], and pneumatic [6] are the most common. Here, many designs and architectures are possible but in general, two principal types stand out. These are reciprocating or piston-like geometries and peristaltic ones [7]. Within the nonmechanical category—devices without moving parts—electro-osmotic [8], magneto-hydrodynamic [9], and electro-hydrodynamic [10] drivers are often employed. The geometries related to nonmechanical pumps are quite simple and similar to each other. Normally, they simply consist of a linear channel connecting two reservoirs.