Modification of surface properties of microfluidic devices
Inventors
RITCHEY, Joshua • Xue, Yi • MELTZER, Robert
Assignees
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Publication Number
US-12551889-B2
Publication Date
2026-02-17
Expiration Date
Abstract
Compositions, devices, and methods are disclosed for the modification of polymer surfaces with coatings having a dispersion of silicone polymer and hydrophobic silica. The surface coatings provide the polymer surface with high hydrophobicity, as well as increased resistance to biofouling with proteinaceous material. The polymer surfaces can be particularly useful in microfluidic devices and methods that involve the contacting of the covalently modified polymer surfaces with emulsions of aqueous droplets containing biological macromolecules within an oil carrier phase.
Core Innovation
A device includes a microfluidic channel having an inner coated polymer surface. The inner coated polymer surface comprises a substrate layer comprising a hydrophobic polymer and a coating layer comprising a silicone polymer and hydrophobic silica, and the coating layer is adsorbed to at least a portion of the substrate layer.
The coated polymer surface is defined by the silicone polymer and hydrophobic silica composition in the coating layer. In described embodiments, the silicone polymer has a molecular weight of 1000 to 10,000 Da and the silicone polymer-to-hydrophobic silica mass ratio is 1.5:1 to 15:1. The coating can include polydimethylsiloxane and is characterized by high hydrophobicity, including water contact angle greater than 100°.
The described coated surfaces achieve improved anti-biofouling performance when exposed to bovine serum albumin. The performance is characterized by reduced water-contact-angle change after exposure to an aqueous 1 mg/mL BSA for 1 hour, and the combined coating maintains hydrophobicity and resists BSA-induced loss of hydrophobicity.
Claims Coverage
The independent claim defines a microfluidic channel device with an inner coated polymer surface combining an adsorbed silicone polymer/hydrophobic-silica coating on a hydrophobic polymer substrate layer. The dependent claims add multiple inventive features, including specific silicone polymer identity, molecular-weight and mass-ratio ranges, and hydrophobicity and BSA-related contact-angle performance thresholds.
Adsorbed silicone polymer and hydrophobic silica coating on a hydrophobic polymer substrate
A microfluidic channel has an inner coated polymer surface comprising a substrate layer comprising a hydrophobic polymer and a coating layer comprising a silicone polymer and hydrophobic silica, wherein the coating layer is adsorbed to at least a portion of the substrate layer.
Silicone polymer molecular weight range
The silicone polymer has a number average molecular weight of 1000 Da to 10,000 Da.
Silicone-to-hydrophobic silica mass ratio range
The coating layer has a mass ratio of the silicone polymer to the hydrophobic silica of 1.5:1 to 15:1.
Polydimethylsiloxane coating material
The silicone polymer is polydimethylsiloxane.
Hydrophobicity via water contact angle threshold
The coated polymer surface has a water contact angle greater than 100°.
BSA durability via limited contact-angle change
The water contact angle changes by less than 10° after exposure to an aqueous 1 mg/mL bovine serum albumin solution for 1 hour.
Across the independent claim and dependent refinements, the claim coverage centers on an adsorbed silicone polymer/hydrophobic-silica coating on a hydrophobic polymer substrate for microfluidic channels, with further constraints on silicone identity, molecular weight, silicone-to-silica mass ratio, and hydrophobicity and BSA-exposure contact-angle performance.
Stated Advantages
High hydrophobicity, including water contact angle greater than 100°.
Improved anti-biofouling performance characterized by reduced water-contact-angle change after exposure to aqueous 1 mg/mL BSA for 1 hour.
Documented Applications
Use in microfluidic devices with coated channel surfaces based on the described hydrophobic polymer substrate and silicone polymer/hydrophobic silica coating.
Use with emulsion-transport methods using the coated channel surfaces.
Referenced as relevant to polymerase chain reaction (PCR) and digital PCR/droplet digital PCR (DDPCR) contexts in the described microfluidic/emulsion-related entities [procedural detail omitted for safety].
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