Cross-flow microfilters were constructed on silicon substrates using photolithography, chemical vapor deposition, and sacrificial etching. These devices consist of an array of channels with arch-shaped cross-sections approximately 50 μm tall and 140 μm wide. Pores, 5 μm in diameter, were etched through channel walls with a high packing density. The microfilters were analyzed by imaging permeate and retentate solutions down the length of the channels to determine percentages of fluorescent microbeads (diameters of 2.2 and 15.5 μm) filtered per length. A simple model using principles of Brownian motion and Monte Carlo simulation closely predicts filtration performance.
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Barber J, Lunt E, George Z, Yin D, Schmidt H, Hawkins A (2006) Integrated hollow waveguides with arch-shaped cores. IEEE Photonics Technol Lett 18:28–30. doi:10.1109/LPT.2005.859990
Borchardt MA, Spencer SK (2002) Concentration of Cryptosporidium, microsporidia and other water-borne pathogens by continuous separation channel centrifugation. J Appl Microbiol 92:649–656. doi:10.1046/j.1365-2672.2002.01570.x
Cai B, Deitch EA, Ulloa L (2010) Novel Insights for systemic inflammation in sepsis and hemorrhage. Mediators Inflamm. doi:10.1155/2010/642462
Crowley TA, Vincent P (2005) Isolation of plasma from whole blood using planar microfilters for lab-on-a-chip applications. Lab Chip 5:922–929. doi:10.1039/B502930A
Dickson MN, Amar L, Hill M, Schwartz J, Leonard EF (2012) A scalable, micropore, platelet rich plasma separation device. Biomed Microdevices 6:1095–1102. doi:10.1007/s10544-012-9675-2
Gangadharan S, Kusnetsov AV, Zhu H, Hinestroza J, Jasper WJ (2012) Modeling of cross-flow across an electrostatically charged monolith filter. Part Sci Technol 30:461–473. doi:10.1080/02726351.2011.604394
Haeberle S, Zengerle R (2007) Microfluidic platforms for lab-on-a-chip applications. Lab Chip 7:1094–1110. doi:10.1039/B706364B
Jiang H, Weng X, Li D (2011) Microfluidic whole-blood immunoassays. Microflud Nanofluid 10:941–964
Kim M, Zydney AL (2006) Theoretical analysis of particle trajectories and sieving in a 2-dimensional cross-flow filtration system. J Membr Sci 281:666–675. doi:10.1016/j.memsci.2006.04.037
Liu Y, Yu J, Du M, Wang W, Zhang W, Wang Z, Jiang X (2012) Accelerating microfluidic immunoassays on filter membranes by applying vacuum. Biomed Microdevices 14:17–23
Lunt E, Wu B, Keeley J, Measor P, Schmidt H, Hawkins A (2010) Hollow ARROW waveguides on self-aligned pedestals for improved geometry and transmission. IEEE Photonics Technol Lett 22:1147–1149. doi:10.1109/LPT.2010.2051145
Mark D, Haeberle S, Roth G, Stetten F, Zengerle R (2010) Microfluidic lab-on-a-chip platforms: requirements, characteristics and applications. Chem Soc Rev 39:1153–1182. doi:10.1039/B820557B
Peskoller C, Niessner R, Seidel M (2009) Cross-flow microfiltration system for rapid enrichment of bacteria in water. Anal Bioanal Chem 393:399–404
Reynolds DT, Slade RB, Sykes NJ, Jonas A, Fricker CR (1999) Detection of Cryptosporidium oocytes in water: techniques for generating precise recovery data. J Appl Microbiol 87:804–813
Richardson J, Coulson J, Harker J, Backhurst J (2002) Coulson and Richardson’s chemical engineering, 5th edn. Butterworth-Heinemann, Oxford
Roh S, Shin H, Kim S (2006) Backflushing, pulsation and inline flocculation techniques for flux improvement in crossflow microfiltration. Korean J Chem Eng 23:391–398
Sun X, Peeni BA, Yang W, Becerril HA, Woolley AT (2007) Rapid prototyping of poly(methyl methacrylate) microfluidic systems using solvent imprinting and bonding. J Chromatogr A 1162:162–166. doi:10.1016/j.chroma.2007.04.002
van Ruler O, Schultz MJ, Reitsma JB, Gouma DJ, Boermeester MA (2009) Has mortality from sepsis improved and what to expect from new treatment modalities: review of current insight. Surg Infect (Larchmt) 10:339–348. doi:10.1089/sur.2008.012
Warkiani ME, Lou C, Liu H, Gong H (2012) A high-flux isopore micro-fabricated membrane for effective concentration and recovering of waterborne pathogens. Biomed Microdevices 14:669–677
Xuan J, Hamblin M, Stout J, Tolley H, Maynes R, Woolley A, Hawkins A, Lee M (2011) Surfactant addition and alternating current electrophoretic oscillation during size fractionation of nanoparticles in channels with two or three different height segments. J Chromatogr A 1218:9102–9110. doi:10.1016/j.chroma.2011.10.005
Yang S, Undar A, Zahn JD (2006) A microfluidic device for continuous, real time blood plasma separation. Lab Chip 6:871–880. doi:10.1039/B516401J
We wish to acknowledge the following for assistance in device fabrication and data gathering: Brigham Young University’s Integrated Microfabrication Laboratory and Jie Xuan. Financial support was provided by the Ira A. Fulton College of Engineering and the Micron Foundation.
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Ehlert, S.A., Ives, N. & Hawkins, A.R. Cross-flow microfilters with large-diameter sacrificially etched cross-sections. Microfluid Nanofluid 16, 465–471 (2014). https://doi.org/10.1007/s10404-013-1237-2