Microfluidics

Microfluidic devices move picoliters to microliters of fluid through channels narrower than a human hair, for diagnostics, organ-on-chip models, droplet assays and chemical synthesis. Whether a device is prototyped in a research lab or made in volume by a chip manufacturer, it usually starts as layers of PDMS, glass or plastic bonded together, and that bond depends on surface chemistry. A short plasma treatment activates both surfaces so they seal permanently on contact, and it also makes channels hydrophilic and ready for coatings. That is why Harrick Plasma Cleaners appear in about 3,000 microfluidics papers, from Lab on a Chip and Nature Protocols to Nature Communications and Science Advances.

How plasma treatment is used in microfluidics

Bonding PDMS to glass and PDMS. Air or oxygen plasma converts the PDMS surface to silanol groups, which form strong, irreversible siloxane bonds when pressed against plasma-treated glass or PDMS. More than 2,000 papers in our database use this step, most often with 30 seconds to 2 minutes of treatment. See PDMS Bonding for details.

Thermoplastic and 3D-printed chips. PMMA, cyclic olefin polymers and copolymers, polycarbonate, polystyrene and printed resins are plasma activated to improve wetting, adhesive and thermal bonding, and silane-assisted bonding to PDMS. See PMMA Microfluidics, COP Microfluidics, Polycarbonate Microfluidics and 3D Printing.

Hydrophilic channels and surface coatings. Plasma leaves channels hydrophilic so aqueous samples fill without bubbles, and it provides the reactive surface for silanes, PEG and protein coatings. See APTES.

Cell culture and organ-on-chip. Plasma-bonded devices with activated, protein-coated surfaces support cell culture, organoids and multi-tissue organ-on-chip models. See Microfluidic Cell Culture, Organ on a Chip and Organoids.

Droplets, sensing and single-cell analysis. Plasma bonding and surface control are the starting point for droplet generators, acoustofluidic devices, bacteria sensors and single-cell sequencing platforms. See Acoustofluidics, Bacteria Sensors and Single Cell Sequencing.

Where Harrick users apply microfluidics. Hundreds of papers in our database come from genomics and single-cell analysis, diagnostics and point-of-care testing, and chemical synthesis and nanoparticle production, with dozens more in drug development, organ-on-chip and barrier models, and environmental monitoring.

Building a microfluidic device? Tell us your materials, device size and how many chips you make at a time and we will point you to published conditions from Harrick users and the right configuration. Request a Quote or email info@harrickplasma.com.

Why Harrick Plasma for microfluidics

• Proven in the literature. Harrick Plasma Cleaners are cited in over 8,500 peer-reviewed publications, including about 3,000 on microfluidics.
• Strong, consistent bonds. MHz-frequency RF gives strong PDMS-to-glass adhesion; a published comparison found kHz plasma gave more variable bonding (Chau et al. 2011).
• No electrode inside the chamber. RF is coupled from an external coil, so nothing is sputtered onto your chips, and the plasma treats every exposed surface of a molded part.