title: Characterization of thermoplastic microfiltration chip for the separation of blood plasma from human blood.
abstract: In this study, we developed a fully thermoplastic microfiltration chip for the separation of blood plasma from human blood. Spiral microchannels were manufactured on a PMMA substrate using a micromilling machine, and a commercial polycarbonate membrane was bonded between two thermoplastic substrates. To achieve an excellent bonding between the commercial membrane and the thermoplastic substrates, we used a two-step injection and curing procedure of UV adhesive into a ring-shaped structure around the microchannel to efficiently prevent leakage during blood filtration. We performed multiple filtration experiments using human blood to compare the influence of three factors on separation efficiency: hematocrit level (40%, 23.2%, and 10.9%), membrane pore size (5μm, 2μm, and 1μm), and flow rate (0.02 ml/min, 0.06 ml/min, 0.1 ml/min). To prevent hemolysis, the pressure within the microchannel was kept below 0.5 bars throughout all filtration experiments. The experimental results clearly demonstrated the following: (1) The proposed microfiltration chip is able to separate white blood cells and red blood cells from whole human blood with a separation efficiency that exceeds 95%; (2) no leakage occurred during any of the experiments, thereby demonstrating the effectiveness of bonding a commercial membrane with a thermoplastic substrate using UV adhesive in a ring-shaped structure; (3) separation efficiency can be increased by using a membrane with smaller pore size, by using diluted blood with lower hematocrit, or by injecting blood into the microfiltration chip at a lower flow rate.
authors.affiliation: Department of Mechanical Engineering, National Taiwan University of Science and Technology , Taipei, Taiwan.
authors.forename: Pin-Chuan
authors.initials: PC
authors.lastname: Chen
authors.affiliation: Department of Mechanical Engineering, National Taiwan University of Science and Technology , Taipei, Taiwan.
authors.forename: Chih-Chun
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University , Tainan, Taiwan.
authors.forename: Kung-Chia
authors.initials: KC
authors.lastname: Young