Piezoelectric Micropumps for Microrobotics: Operating Modes Simulating and Analysis of the Main Parameters of the Fluid Flow Generation

Abstract

The operation of a piezoelectric micropump, consisting of a resilient elastic microtube of circular cross-section and a system of ring piezoelectric actuators placed on it, which forms a flow of the working fluid by radial compression, is simulated. The flow created by the oscillations of the piezoelectric actuators according to certain schemes is numerically studied: with a symmetric scheme; the average time flow rate of the liquid is zero; with an asymmetric scheme, it is possible to generate a nonzero time-average flow in the positive direction. It was found that the operation mode of the device according to an asymmetric scheme will allow using it as a piezoelectric micropump having a small size and allowing to pump small volumes of liquid. It is also shown that in an asymmetric mode of operation, with an increase in the frequency of oscillations of the piezoelectric actuators and with an increase in their quantity, the average pumped volume of liquid increases, and with a decrease in the radius of the channel, it decreases. An approximate analytical formula is obtained that relates the main parameters of the operating mode (time to reach the operating mode and average fluid flow rate) with the system parameters (the number and frequency of oscillations of the piezoelectric actuators, the radius of the microchannel), which makes it possible to construct an element of the computational module for evaluating the operating modes of the device in question, as well as manage the device itself in real time.