Numerical simulation of pulse-width-modulated micropumps with diffuser/nozzle elements

This paper presents the numerical simulation of a new control method for dynamic micropumps with diffuser/nozzle elements: the pulse-width-modulation (PWM) of the drive signal. A piezo disk with a square wave signal actuates the pump, the square-wave-like deflection of the membrane causes velocity pulses in opposite directions. Because of the inertia of the fluid in the pump chamber, the time distance between these velocity pulses controls the generated flow rate. The paper compares results of models with different boundary conditions of the pump membrane: time-dependent velocity and time-dependent deflection. This paper also describes the fabrication of pump prototype based on laser micromachining. Simulation results are then compared to experimental results.