SlipStream™ microfluidics technology is a process by which IDEX Health & Science, LLC's plasma activated PDMS BioGasket™ technology and world class precision machining expertise are married to produce laminated microfluidic devices with unparalleled optical and fluidic characteristics. Microfluidic features are primarily formed in PDMS layers using a maskless technology, and vias are formed in the other material layers. However, our unique processes allow us to manufacture SlipStream™ microfluidics using a surprising array of materials. We have develop proprietary processes for plasma bonding PDMS to many polymers (COC, COP, polysulfone, polyester, polyethylene and many others), silicon, sapphire, ceramics (aluminum nitride, silicon carbide, alumina, etc.), glass and to PDMS itself. Our ability to use such a wide array of materials opens up the device design space well beyond the traditional thinking. You can use combinations of these materials, including constructions that have microstructures in all layers.
The layered construction of the PDMS-based SlipStream™ technology differs considerably from traditional soft lithography in that only the wall edges of the microfluidic channels come in contact with fluids. The smaller PDMS surface area that comes into contact with fluid minimizes the potential of small molecule absorption into PDMS surfaces, gas diffusion into the fluid and low molecular weight siloxanes migrating out of the PDMS. When necessary, proprietary extraction processes are used to remove low molecular weight siloxanes from the PDMS layers and thereby preventing PDMS interaction with hydrophobic elements of cell membranes and delaying the native PDMS hydrophobic recovery for weeks to months.
The details of manufacturing specific microfluidic devices depend on the device size, design requirements, production volume and cost targets. In some instances, we manufacture microfluidic devices in large sheets and then dice them to final size. This approach has the obvious advantage of scale. In other cases, we precut and drill windows and assemble each device individually. This approach is particularly attractive for larger devices with high degrees of integration and functional parallelism.
SlipStream™ Technology Advantages
- Pristine Optical Characteristics: Because SlipStream™ technology uses low temperature and pressure during the bonding processes, the top and bottom windows do not warp, dimple or discolor during assembly. In addition, SlipStream™ does not use etching so it produces pristine flatness and surface roughness in the fluidic channels. SlipStream™ is the only viable way to produce cost effective microfluidics made from difficult to deep-etch materials such as fused silica.
- Many Material Choices: SlipStream™ technology is the only technology that can use any combination of top and bottom window materials in the microfluidic device construction - not just CTE matched materials. Microfluidic devices can be manufactured from borosilicate glass, fused silica, quartz, silicon, sapphire, COC, COP, polysulfone, polyester, polyethylene and many other plastics and ceramics. Add microstructutures to any layer or material. This allows ultimate flexibility to choose the best materials for application.
- Streamlined Prototyping and Manufacturing: No masks are required because SlipStream™ microfluidics use micro-robotic cutting to manufacture the channels. As a result, the technology is ideal for prototyping and volume production alike.
- Design Flexibility: With micro-robotic cutting, a wide range of fluidic geometries can be created with little or no hardware changes. It is as simple as loading a new CAD file.
- Three Dimensional Constructions: With low temperature and pressure bonding, SlipStream™ technology makes it easy to manufacture microfluidics with complex, multilayer flow paths.
There are many technologies capable of producing layers used in laminated microfliudics. The table below provides a high level comparison of the leading technologies.
|SlipStream™||DRIE||HF Etching||Powder Blasting||Photosensitive Glass Etching (*)|
|Channel Depth||25um - >1mm||0.1 - 500um||0.1 - 100um||25um - >1mm||25um – 1mm|
|Channel Surface Roughness (Ra)||<2nm||<2nm||~100nm||1um||1um|
|Materials||Any Glass, Fused Silica, Silicon, SiC, AlN, Polymers, others||Borosilicate Glass,
Fused Silica, Silicon
|Bonding Technology||Low Temperature/ Pressure||High Temperature/Pressure|
|Warping During Bonding||No||Yes|
|(*) Foturan has a medium level of autofluoresence, meaning its autofluoresence is higher than borosilicate glass and PDMS. See the table provided in flow cell materials page for a ranking of the autoflurosence of the materials CiDRA®< Precision Services, LLC uses.|
|Optical Flatness (all surfaces)||Less than 500nm/mm|
|Bottom & Top Plate Thickness||100um to >1cm|
|Top & Bottom Plate Thickness Tolerance||Less than +/-20um|
|Top & Bottom Plate Parallelism Tolerance||Less than +/-10um|
|Channel Thickness||15um to 700um|
|Channel Width||100um to >1cm|
|Channel Dimensional Accuracy||+/-20um|
|Standard Gasket Colors||Clear, White|
|Surface Roughness (Ra) for All Optical Surfaces||<2nm|
|Scratch/Dig Within Clear Aperture||10um/20um|
|Maximum Operational Temperature||170°C|
|Maximum Pressure||100psi (*)|
|(*) Design dependent|