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Cell sorting is an important diagnostic tool used in various aspect of medical prognosis. Numerous cell sorting techniques are currently available on market but they are quite bulky, expensive and at the same time requires very trained operators. In this paper we report on wafer level fabrication technique that will allows for a small form factor device targeting cell sorting. We give detailed overview for the fabrication of our miniaturized cell sorter that is formed with a CMOS compatible process. It used standard fabrication technique in combination with photo-patternable polymer, that has excellent properties for microfluidics applications. The ability to process on wafer level distinguish this from other processes, whose yields are limited to few test samples. The device fabrication includes: processing of micro-heaters, definition of polymer microfluidic channels and collective die-to-wafer bonding of glass substrate onto the polymer channels. We report on the initial characterization of the cell sorting targeting sorting rate and sorting yield. We have achieved sorting rate of 5,000 cells/s and yield of 70% is obtained in initial investigations.

Cell sorting is an important diagnostic tool in medical field to separate different type of cells. Various techniques are employed for sorting with main mechanism being cell analysis and then separation either by electric or magnetic field. In this paper we explain the fabrication process for tungsten micro-heaters on silicon and polymer microfluidic for a formation of a generic platform that can be used for the various cell sorting applications. Polymer material is not only used for the formation of channel for fluidics movement but also used as bonding interface between the silicon wafer and the glass. We report on the bonding strength of the polymer material. It shows that our devices can withstand a pressure in excess of 3 bar which is more than sufficient for most microfluidic applications such as cell sorting. Characterization of micro stream bubble generation life cycle is presnted. The sorting efficiency of our device is reported, with initial characterization done beads to determine sorting rate and sorting yield. We achieved sorting rate of 1,000 beads/s with sorter purity of up to 98 % in initial investigations.

Integration of microelectronics with microfluidics enables sophisticated lab-on-a-chip devices for sensing and actuation. In this paper, we investigate a novel method for in-situ microfluidics fabrication and packaging on wafer level. Two novel photo-patternable adhesive polymers were tested and compared, PA-S500H and DXL-009. The microfluidics fabrication method employs photo lithographical patterning of spin coated polymer films of PA or DXL and direct bonding of formed microfluidics to a top glass cover using die-to-wafer level bonding. These new adhesive materials remove the need for additional gluing layers. With this approach, we fabricated disposable microfluidic flow cytometers and evaluated the performance of those materials in the context of this application. DXL-009 exhibits lower autofluorescence compared to PA-S500H which improves detection sensitivity of fluorescently stained cells. Results obtained from the cytotoxicity test reveals that both materials are biocompatible. The functionality of these materials was demonstrated by detection of immunostained monocytes in microfluidic flow cytometers. The flexible, fully CMOS compatible fabrication process of these photo-patternable adhesive materials will simplify prototyping and mass manufacturing of sophisticated microfluidic devices with integrated microelectronics. ispartof: Biomedical Microdevices vol:20 issue:1 pages:2- ispartof: location:United States status: published

Safe, high-rate and cost-effective cell sorting is important for clinical cell isolation. However, commercial fluorescence-activated cell sorters (FACS) are expensive and prone to aerosol-induced sample contamination. Here we report a microfluidic cell sorter allowing high rate and fully enclosed cell sorting. The sorter chip consists of an array of micro heating hotspots. Pulsed resistive heating in the hotspots produces numerous micro vapor bubbles with short duration, which gives rise to a rapid jet flow for cell sorting. With this method, we demonstrated high sorting rate comparable to commercial FACS and the significant enrichment of rare cancer cells. This vapor bubble based cell sorting method can be a powerful tool for contamination-free and affordable clinical cell sorting such as circulating tumor cell isolation and cancer cell therapy. crosscheck: This document is CrossCheck deposited related_data: Supplementary Information identifier: Koen de Wijs (ORCID) copyright_licence: The Royal Society of Chemistry has an exclusive publication licence for this journal history: Received 20 December 2016; Accepted 23 February 2017; Accepted Manuscript published 23 February 2017; Advance Article published 2 March 2017; Version of Record published 29 March 2017 ispartof: Lab on a Chip vol:17 issue:7 pages:1287-1296 ispartof: location:England status: published