The next generation of Point-of-Care (PoC) tests based on microfluidics promises to revolutionize the world of medical diagnostics, e.g. for personalized medicine and companion diagnostics. Moreover, microfluidic devices can be used in other application areas like pharma, agri-food, environmental monitoring and forensics.

Surfix has developed nanocoatings to optimize the surface properties of glass and polymer microfluidics. Our nanocoatings enable control of wettability, flow properties and non-specific adsorption of biomolecules. Moreover, combining different nanocoatings in a single device is also possible. Surfix’s nanocoatings are designed to be compatible with bonding (‘closing’) of the device and can be combined with biofunctionalization.

Polymer Microfluidics

Polymers are the most popular materials for the fabrication of microfluidic devices. However, proteins tend to adsorb to these materials, causing biofouling. Moreover, commonly used thermoplastics such as COC (Cyclic Olefin Copolymer) are hydrophobic, thus hampering capillary flow of (biological) liquids.

Surfix offers nanocoating-enabled microfluidics with hydrophilic, antifouling surface properties by (local) control of wettability and biomolecular interactions.

Moreover, combining coating with bonding (‘closing’) of the chip in a scalable manufacturing process is a persistant challenge in microfluidics. Surfix's Coat & Close technology integrates coating and bonding in a single process, resulting in strongly bonded devices with hydrophilic, antifouling surfaces.

Benefits of Surfix's nanocoatings for polymer microfluidics:

  • Passive transport by capillary flow
  • Prevents biofouling
  • Stable, i.e. no surface rearrangement
  • Can be applied locally
  • Compatible with common (thermoplastic) polymers used in microfluidics
  • Bonding of hybrid devices
  • Cost effective and scalable

The animation below shows Surfix's hydrophilic, antifouling nanocoating in action. A custom hydrophobic plastic is coated with a hydrophilic antifouling coating, enabling capillary flow and multiplexing of antibodies. The hydrophilic bonding allows to close the COC microfluidic onto other plastics or even hybrid materials with our proprietary Coat & Close process.

Glass microfluidics

In contrast to polymers, glass is hydrophilic by itself. Therefore, hydrophobic nanocoatings are often required to control wettability. Another important difference between glass and polymer microfluidics is that coatings in glass devices generally have to be applied after bonding, i.e. in closed channels. Using Surfix's nanocoatings, glass devices with optimized surface properties can be obtained.

Besides applying a uniform nanocoating, Surfix's local nanocoating technology also allows the combination of hydrophobic and hydrophilic areas in a single device. For example, hydrophobic patches may serve as flow stoppers, or are used to guide the flow inside the channel along a predefined pathway.

Benefits of Surfix's nanocoatings for glass microfluidics:

  • Fast one-step nanocoating process
  • Coating inside bonded devices
  • Patterning with µm-scale resolution
  • Highly hydrophobic surfaces (water contact angle >130°)
  • Control of wettability and flow properties
  • Guided flow along predefined flow paths

The video below shows an aqueous dye solution flowing through a glass microfluidic channel (courtesy of the HEIDENHAIN Group) with Surfix’s patterned hydrophobic nanocoating. The liquid is confined to the non-coated hydrophilic areas and spontaneously follows the flow path defined by the nanocoating.

Hybrid microfluidics

For many applications hybrid devices are required in which different components and materials are used. For example, a polymer microfluidic device has to be integrated with a silicon sensor chip, or glass and polymer parts are combined in a microfluidic cartridge with advanced functionalities.

Surfix has developed nanocoatings for both polymer and glass microfluidics, and can also work with hybrid devices. Moreover, Coat & Close provides a unique process for coating and bonding that can also be applied to hybrid devices.

For more information on our product offer, please contact us.