High-throughput microcapillary pump with efficient integrated low aspect ratio micropillars

Abstract

Prediction and reduction of pressure drop and resistance flow in micropillar arrays are important for the design of microfluidic circuits used in different lab-on-a-chip and biomedical applications. In this work, a diamond microchannel-integrated micropillar pump (dMIMP) with a resistance flow 35.5 % lower than a circular-based micropillar pump (cMIMP) has been developed via the optimization of the fluid dynamic behavior of different pillar shapes in a low aspect ratio (H/D ranged from 0.06 to 0.2) integrated pillar microchannel. The effect of different geometrical parameters (such as pillar shape and its distribution) has been considered to minimize the microchannel resistance flow. Six-micrometer-depth polidimetilsiloxane (PDMS) channels have been fabricated using a modified soft lithography process, which prevents the PDMS deformation under high-pressure operation. Flow through the fabricated samples has been numerically solved and experimentally measured, with an agreement higher than 90 %. The results have been used to validate the derived analytical formulation to determine the flow resistance in this type of channels, a fast approach to obtain the resistance flow in the design stage of microdevices. The analysis of the results indicates that, although porosity can be a determinant parameter to predict the resistance flow of MIMP, other geometrical parameters such as side distance between pillars and pillar shape play a major role in this scenario. Finally, a high-throughput optimized diamond MIMP pump has been designed, tested and validated as a capillary pump, showing that it can provide a flow rate 73 % higher than a circular MIMP pump.Peer ReviewedPostprint (published version

Self-driven filter-based blood plasma separator microfluidic chip for point-of-care testing

“…3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 also paves the path for collecting the separated plasma in the top part using multiple collected channels due to a filled distributed area with blood plasma. Its design is the result of our previous work for developing a high-throughput microcapillary pump with efficient integrated low aspect ratio micropillars [40]. The obtained results indicated that the diamond pillar array presents the minimum resistance flow compared to the other pillar shapes.…”

“…To reach this aim, according to Madadi et al [40]; the diamond post shape with increased side distance between pillars is the most efficient design for minimizing the MIMP channel flow resistance and it can be calculated through where µ is the fluid viscosity, L is the length of microchannel, w is the half depth of microchannel, H is the height of microchannel and ε is the porosity [40]. Since the fluid and the height of the channel are fixed, we have maximized the porosity to achieve a manufacturable device.…”

High-performance PCB-based capillary pumps for affordable point-of-care diagnostics

“…In the work of Madadi et al (2014), an extensive investigation of both the micropillar geometry and array topology on the hydraulic resistance was presented. The authors examined a large variety of micropillar shapes and offered a detailed comparison between these, describing optimal architectures to ensure minimum flow resistances.…”

“…Equations (1) and (2) define the relation between the design parameters (MFS, FD, D, SD and LD) of the diamond and circular architectures, respectively, derived from the experimental results in micropillar capillary pump flow rate performance of Madadi et al (2014).…”

“…Juncker et al (2002) reported an autonomous microfluidic capillary system transporting aliquots of different liquids from the inlets through a reaction chamber into the capillary pumping component comprising three microchannels. The performance of this technology was enhanced by Zimmermann et al (2007), who studied the effect of various capillary pumping structures, while more recently Madadi et al (2014) optimised the shape of micropillars and studied the effect of the geometry of the pillar array.…”