Driving complex flow waveforms with a linear voice coil actuator

Abstract

Oscillatory and pulsatile fluid flows for use in microfluidic applications were generated using a deformable chamber driven by a low cost linear voice coil actuator. Compliance in the fluidic system originating in the deformable chamber and the fluidic tubing produced a strong frequency dependence in the relationship between the system's input and the output flow rate. The effects of this frequency dependence were overcome by precise system calibration, enabling on-demand generation of sinusoidal oscillations in the fluid flow rate with a controlled amplitude in the range from 0.1 to over 1 ml/min across a frequency range from 0.1 Hz to 10 Hz. The calibration data further enabled the optimization of a multistage exponential smoothing model of the system that allowed the generation of arbitrary complex waveforms. This was demonstrated by combining flow modulation with a constant background flow generated by a syringe pump to mimic the pulsatile flow found in the human vascular system.