Microinjection molded disposable microfluidic lab-on-a-chip for efficient detection of agglutination

Abstract

Previous diagnosing methods based on agglutination have a limitation in view of emergency and pointof-care diagnoses due to the requirement of large scale equipments and much agglutination time. In this paper, we propose a low cost microfluidic lab-on-a-chip for more efficient detection of agglutination. In the present lab-on-achip, two inlet microwells, flow guiding microchannels, chaotic micromixer and reaction microwell are fully integrated. Mold inserts for the lab-on-a-chip were manufactured by UV photolithography and nickel electroplating process. The complete lab-on-a-chip was realized by the microinjection molding of cyclic olefin copolymer and the subsequent thermal bonding. The improved serpentine laminating micromixer, developed by our group, integrated in the lab-on-a-chip showed the high-level of chaotic mixing, thereby enabling us to get a reliable mixing of sample and reagent. The performance of the fabricated labon-a-chip was demonstrated by agglutination experiments with simulated bloods of 10 ll and simulated sera of 10 ll. The results of agglutination inside the reaction microwell were clearly read by means of the level of light transmission. The present microfluidic lab-on-a-chip could be widely applied to various clinical diagnostics based on agglutination tests.

Polymeric-Based In Vitro Diagnostic Devices

“…Complicated porous geometry, for example, photopolymerized polymer monoliths in microchannels, is another approach to enhance mixing and improve overall chemical reaction efficiency [197]. The applications of mixers are easily coupled with other actuation and sensing mechanisms for pathogen DNA detection and various clinical diagnostics [76,198].…”

“…The high pressure and temperature ranges used when molding limits the use of silicon, glass, resists, and other polymers as mold material, so metal materials are commonly chosen [73]. Those molds with micrometer resolution for LOC applications are usually fabricated using standard photolithography techniques followed by electroplating to prolong the mold's lifetime [74][75][76]. A master mold can withstand more than 200 cycles without severe deformation [77].…”

Cyclic olefin polymers: emerging materials for lab-on-a-chip applications

“…The high temperature and pressure ranges used when moulding, limits the use of silicon (Si), resists and other polymers as mould material, thus metals are commonly chosen (Kim et al 2006). The mould inserts are typically fabricated by standard photolithography techniques [for instance, using SU-8 (Kim et al 2006) or AZ4620 resist (Appasamy et al 2005)], followed by electroplating (Chen et al 2008b;Choi et al 2009;Mccormick et al 1997;Mela et al 2005).…”

“…in organic electrochemistry applications. COPs also present a high biological inertness that makes them suitable for biomedical applications (Bhattacharyya and Klapperich 2006;Choi et al 2009), allow long-term stable surface treatments (Huang et al 2000;Hwang et al 2008;Steffen et al 2007), and provide a low water absorption (Japan Synthetic Rubber 2009;Mitsui Chemicals America 2009;Topas Advanced Polymers 2009;Zeon Chemicals 2009). Low water absorption is beneficial to ensure that the dimensions of the structures do not change with the environmental conditions.…”

A process analysis for microchannel deformation and bonding strength by in-mold bonding of microfluidic chips

“…However, the bonding pressure cannot be well controlled. Some researchers [10][11][12][13][14] used a hot press machine or homemade experimental apparatus to bond the substrate and cover sheet. By these methods, bonding pressure can be controlled, but the bonding time increases owing to the slow preheating process.…”