Development of peristaltic antithrombogenic micropumps for in vitro and ex vivo blood transportation tests

Abstract

This study involves the design, fabrication and characterization of a biocompatible silicon micropump. Three experiments were conducted to study the performance of this pump in clinical environments. They were a blood compatibility test, and in vitro and ex vivo studies. Whole blood is an intrinsically complex material and difficult to manipulate using a microsystem device. In the blood compatibility experiments, two materials N-(triethosilylpropyl)-O-polyethylene oxide urethane (PEOU) and polyethylene glycol (PEG) were employed to form a self-assembled monolayer (SAM) on a chip surface. According to the platelet remaining test and a 30-min blood transportation test, PEOU protected the micropump from thrombus. In the second experiment, the micropump handled several liquids, including DI water and whole blood. When the pump was operated at a voltage of 140 Vpp, the flow rates of the DI water and whole blood were 121.6 μl/min at 500 Hz and 50.2 μl/min at 450 Hz, respectively. The maximum back pressure of the water and the blood in the micropump were 3.2 and 1.8 kPa, respectively. Finally, the micropump injected phosphated buffered saline (PBS) and whole blood into the veins of rats. The pump was characterized ex vivo and discussed. The third experiment reveals that the micropump fulfilled the dosing condition for clinical medicine and did not affect the physiological function of the rats. This pump is highly promising for biomedical applications, such as in drug delivery for patients, or in clinical care. Moreover, the pump has potentials to control precisely medication to improve conventional clinical treatments.