BioGasket™ Technology

BioGasket™ technology is the process by which polydimethylsiloxane (PDMS) material is microformed and plasma activated to form permanent, adhesive-free bonds with common life sciences and medical device materials. CiDRA® Precision Services, LLC uses this technology to custom manufacture highly robust fluidic devices.  While using PDMS for microfluidic devices has been studied for years, CiDRA® Precision Services, LLC’s BioGasket™ technology offers flexible and volume manufacturing friendly solutions. Rather than throwing a hammer at the problem, CiDRA® Precision Services, LLC uses a scalpel. In fact quite literally our approach to device fabrication uses a robotically manipulated microscalpel to create precise gasket geometries. In contrast to some other methods that involve expensive processes like lithography, etching, anodic bonding and laser transformation, BioGasket™ technology utilizes simple, low capital processes and applies precision only where it’s needed.

The BioGasket™ bonding process generally involves the following steps:

  1. Select the PDMS gasket material for thickness, hardness and color.
  2. Create the desired gasket geometry using our proprietary precision robotic microscalpel.
  3. Activate one surface of PDMS sheet with plasma.
  4. Contact PDMS to the selected substrate material.
  5. Press and apply low heat (40°C -100°C) and low pressure (20psi to 100psi).

The plasma activation process readies the PDMS surface to bond to a number of substrates such as glass, ceramic and some plastics by temporarily exposing a surface layer of non-binding Si atoms.  These silicon atoms then find OH groups on the substrate when brought into contact and begin to form permanent covalent bonds.  The bonding process can be thermally accelerated, and once complete is irreversible.  Because the cutting process can be performed on the substrate before bonding is complete, very accurate alignment can be maintained between features on the substrate, such as holes or slots, and the channels.  Typical channel sizes range from 100um to >5 mm wide with geometrical tolerances in the range of +/- 20 um. 

Benefits

  • Bonds to a Wealth of Glass, Ceramic and Crystalline Materials
  • Direct Covalent Bond (No Adhesives)
  • No Leaks After Repeated Use
  • Amazing Variety of Geometric Features
  • Reagent and Biomaterial Compatibility
  • Rapid Prototypes

Applications

  • Hybridization Chambers
  • Microarray Gasket Slides
  • Chambered Coversilps
  • Flow Cells
  • Life Sciences Instrumentation
  • Medical Devices
  • Fluidic Seals of All Types

Chemical Compatibility

  • Acetone, Ethanol, Isopropyl Alcohol
  • Hybridization Buffers
  • Diluted KoH
  • Diluted Bleach
  • Human Blood & Blood Serum
  • Synthetic Oligonucleatides
  • DNA, Proteins & Antibodies
  • Florescent Labels

Advantages

  • Seals Common Life Sciences and Medical Device Materials
  • Optical Grade Glass Structures
  • Complex Gasket Geometries
  • Low Complexity Processes!

Besides its tailorable adhesion properties, PDMS possesses other material qualities that make it ideal for flow cell applications.  Its low autofloruresence, relatively high tensile strength, low stiffness and broad optical transmission range are some of the traits that make Biogaskets™ so attractive. 

Parameter

Specification
Gasket Thickness 25 um to > 700 um
Gasket Thickness Tolerance +/- 5 um (*)
Gasket Cut Width 50 um to > 1cm
Gasket Cut Dimensional Accuracy +/- 30 um
Standard Gasket Colors Clear, White, Red, Black
Gasket Stiffness 20 to 50 Shore A Durameter
Surface Roughness (Ra) for Optical Surfaces <2nm
Scratch/Dig Within Clear Aperture for Optical Surfaces 10um/20um
Maximum Opertional Temperature 200°C
Fluidic Fittings Luer, Barb, Nanoport, Custom Many Other
(*) +/-10um for gasket thickness > 75um