Engineering an extremely high flow rate micropump and integrating with an inertial microfluidics for rapid and efficient blood plasma extraction from fingertip blood with lancets

Abstract

Extracting blood plasma is a necessary step for many medical diagnostics, and inertial microfluidics has attracted significant attention in separating plasma and blood cells from blood. However, external pump was mandatorily needed to generate sufficient flow rate and inertial effect to achieve the separation performance, which led to requirement of blood in mL scale due to the connectors and tubings from the external pump to the microfluidics. An integrated microfluidics was developed herein to rapidly extract blood plasma from only 4 μL whole blood drawn from fingertip with lancet, which included a highly efficient pneumatic peristaltic micropump (PPM) and a spiral inertial microfluidics with trapezoidal cross-sectional areas. Experiment results clearly demonstrated: (1) blood plasma can be rapidly extracted within 3 minutes with efficiency up to 97% from 45X diluted blood, (2) an extremely high flow rate of 3,500 μL/min was recorded with our triple PPM under applied pressure of 300 kPa and operation frequency of 10 Hz, which is competitive to the current commercial external syringe pump, (3) sufficient applied pressure is critical to the performance of PPM, because it can maintain the efficient stroke volume while minimizing the dead volume during iterative pumping process.