A mass manufacturable thermoplastic based microfluidic droplet generator on cyclic olefin copolymer

The rapid progress of droplet microfluidics and its wide range of applications have created a high demand for the mass fabrication of low-cost, high throughput droplet generator chips aiding both biomedical research and commercial usage. Existing polymer or glass based droplet generators have failed to successfully meet this demand which generates the need for the development of an alternate prototyping technique. This work reports the design, fabrication and characterization of a mass manufacturable thermoplastic based microfluidic droplet generator on cyclic olefin copolymer (COC). COC chips with feature size as low as 20 µm have been efficiently fabricated using injection molding technology leading to a high production of inexpensive droplet generators. The novelty of this work lies in reoptimising surface treatment and solvent bonding methods to produce closed COC microchannels with sufficiently hydrophobic (contact angle of 120°) surfaces. These COC based droplet generators were shown to generate stable monodisperse droplets at a rate of 1300 droplets/second in the dripping regime. These new mass manufacturable, disposable and cheap COC droplet generators can be custom designed to cater to the rapidly increasing biomedical and clinical applications of droplet microfluidics.

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