Frit material and bonding method for microfluidic separation devices
AssigneeNanostream, Inc.
InventorsJeffrey A. Koehler, Paren P. Patel
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Abstract
A frit for use in multi-layer microfluidic separation devices is provided. The frit comprises a polymeric membrane that may be securely bonded within the device and minimizes lateral wicking. A secure bond is ensured by treating the polymer to match its surface energy to that of the materials to which it is bound. Treatments include plasma treatment, irradiation and the application of acids.
Claims44
A multi-layer microfluidic separation device comprising:
- a first stencil layer defining the lateral boundaries of a plurality of separation columns;
- a second stencil layer defining the lateral boundaries of a plurality of exit channelswherein each exit channel of the plurality of exit channels is in fluid communication with a separation column of the plurality of separation channels to form a plurality of fluid flow paths;
- and
- a single frit having an upper surface and a lower surface, wherein the upper surface is bonded to the first stencil layer and the lower surface is bonded to the second stencil layer such that the frit layer is disposed within at least two fluid flow paths of the plurality of fluid flow paths;
- wherein the frit permits flow in a direction substantially perpendicular to the upper surface and the lower surface;
- wherein the upper surface is sufficiently bonded to the first stencil layer and the lower surface is sufficiently bonded to the second stencil layer to prevent substantially any lateral flow of fluid at an operating pressure either between the first stencil layer and the frit or between the second stencil layer and the frit.
The multi-layer microfluidic separation device of claim A1 wherein the operating pressure is at least about 10 psi (69 kPa).
The multi-layer microfluidic separation device of claim A1 wherein the operating pressure is at least about 50 psi (345 kPa).
The multi-layer microfluidic separation device of claim A1 wherein the operating pressure is at least about 100 psi (690 kPa).
The multi-layer microfluidic separation device of claim A1 wherein the operating pressure is at least about 500 psi (3450 kPa).
The multi-layer microfluidic separation device of claim A1 wherein each separation column of the plurality of separation columns contains stationary phase material.
The multi-layer microfluidic separation device of claim A6 wherein the stationary phase material includes particulate material having an average particle size.
The multi-layer microfluidic separation device of claim A6A wherein the frit has an average pore size and the average pore size is smaller than the average particle size.
The multi-layer microfluidic separation device of claim A7 wherein the frit has an average pore size and the average pore size is at least about ten times smaller than the average particle size.
The multi-layer microfluidic separation device of claim A1 wherein the frit comprises a permeable polypropylene membrane.
The multi-layer microfluidic separation device of claim A1 wherein the frit comprises a track-etched membrane.
A method for fabricating a multi-layer microfluidic separation device, the method comprising the steps of:
- removing portions of a first device layer to define the lateral boundaries of a plurality of separation columns;
- removing portions a second device layer to define the lateral boundaries of a plurality of exit channels;
- providing a frit having an upper surface and a lower surface, the frit being fabricated with a material that permits flow in a direction substantially perpendicular to the upper surface and the lower surface;
- pre-treating the frit;
- and
- bonding the first device layer, the second device layer, and the frit such that each exit channel of the plurality of exit channels is in fluid communication with a separation column of the plurality of separation channels to form a plurality of fluid flow paths, the upper surface being bonded to the first stencil layer and the lower surface being bonded to the second stencil layer such that the frit layer is disposed within at least two fluid flow paths of the plurality of fluid flow paths, the upper surface and the first stencil layer being sufficiently bonded and and the lower surface and the second stencil layer being sufficiently bonded to prevent substantially any unintended lateral flow of a fluid at an operating pressure either between the first stencil layer and the frit or between the second stencil layer and the frit.
Dependencies are inferred from the claim text.