Active and passive filtering of whole blood for lab-on-chip biosensors

Asad A Akinfolarin, University of Rhode Island


In this thesis work, designs were developed and implemented for separating plasma from a droplet of whole blood in an active and passive Lab-on-Chip (LOC) device. Nine filters were tested and compared to establish a process of elimination based on the filtration properties and performance. An Asymmetric Polysulfone filter (Vivid Plasma Membrane) was selected over other filters for the highest yield of extracted plasma in both active and passive LOC devices. The plasma filtrates extracted from the VP filter were characterized and evaluated using techniques of quantification, Giemsa Staining, an Enzyme-Linked Immunoabsorbent Assay (ELISA), and Blood Cell Count. Results were concluded with a passable detection for a specific analyte, C-Reactive Protein (CRP) in plasma filtrates from EDTA whole blood. Active designs were fabricated using methods of PDMS soft-lithography; however, contrary to the conventional SU-8 photo mask, aluminum molds were designed in Solid Works and created via a rapid prototyping machine. Using this approach, the dimensions of LOC components were customized entirely to control fluid flow and volumes. In addition to the customized layered designs for active LOC devices, a push fit frame was developed to integrate a VP filter to the inlet of any LOC device. Similar to active designs, a passive design was developed conceptually as a three-piece rapid proto-type model made of ABS material. Due to the absence of external forces in the passive design plasma extraction was accomplished using a blotting technique along the bottom surface of the membrane. A series of calculations and functionality tests were conducted to optimize the performance of both devices, serving as a pilot study in the development of a handheld active or passive microfluidic Lab-on-a Chip Biosensor.

Subject Area

Biochemistry|Biomedical engineering|Mechanical engineering

Recommended Citation

Asad A Akinfolarin, "Active and passive filtering of whole blood for lab-on-chip biosensors" (2011). Dissertations and Master's Theses (Campus Access). Paper AAI1500312.