Modeling, Identification, and Flow Control for a Microfluidic Device using a Peristaltic Pump*

This paper presents a method for modeling and controlling pressure at the inlet of a microfluidic lab-on-a-chip device using a peristaltic pump. The principle idea is to alter the voltage provided to a DC peristaltic pump based on the pressure measured at the inlet of the microfluidic device, as a simple, low-cost alternative to standard microfluidic flow control instrumentation. The model accounts for varying resistance and periodic peristaltic pump oscillations, accounting for variable viscosity of the fluid. A model capturing major phenomena with respect to pressure and flow at the inlet of the microfluidic device was developed using the extended Bernoulli equation and peristaltic pump geometry. A proportional-integral-derivative (PID) control system was implemented to achieve specified pressure across varying viscosities. Excellent agreement is obtained between experimental and simulation results using the proposed model. This pressure model can be used to determine various pump and fluidic characteristics in operation of a microfluidic lab-on-a-chip device.