Chromatography apparatus having diffusion-bonded and surface-modified components

Patent metadata

Field	Value
Publication number	US-2017038350-A1
Application number	US-201615231302-A
Country	US
Kind code	A1
Filing date	Aug 8, 2016
Priority date	Mar 26, 2010
Publication date	Feb 9, 2017
Grant date	—

Abstract

A microfluidic device for separating a sample by chromatography includes diffusion bonded metallic sheets joined together to create a hermetically sealed interface between each adjacent metallic sheet without the introduction of a secondary material. Enclosed within the diffusion bonded sheets is a separation channel accessible by at least one of an inlet or an outlet. The separation channel is packed with micrometer-sized particles serving as a stationary phase in a chromatographic separation. Wetted surfaces of the separation channel include a coating of an organic material at least one monolayer thick.

First claim

What is claimed is:

1 . A diffusion-bonded product manufactured comprising the steps of:
supplying two or more substantially compositionally similar metal sheets with each having a flat major surface with no layer thereon to promote bonding; at least one of the two or more metal sheets including at least a portion of a microfluidic channel disposed therein; bringing the flat major surface of each of the two or more metal sheets into a contacting relationship with at least one of the two or more sheets thereby forming an interface and forming and enclosing the microfluidic channel at the interface between such sheets, the microfluidic channel having at least one entrance port and at least one exit port; heating the contacting sheets in a vacuum furnace or an inert-atmosphere furnace to a temperature substantially below melting temperature of such sheets; urging the contacting sheets together under a compressive stress while the sheets are being heated to bond the sheets together by causing grains of the two or more metal sheets to merge across the interface from one sheet to the other sheet; cooling the bonded two or more sheets to about room temperature; and applying at least an organic coating to the microfluidic channel enclosed between the bonded two or more sheets through at least one of the at least one entrance port or the at least one exit port.

2 . The diffusion-bonded product of claim 1 , further comprising the step of:
surface treating wetted surfaces of the microfluidic channel with a vapor after cooling but before applying the organic coating.

3 . The diffusion-bonded product of claim 2 , wherein the vapor deposits amorphous silicon on the wetted surfaces of the microfluidic channel.

4 . The diffusion-bonded product of claim 2 , wherein the vapor deposits a layer of an inorganic-oxide on the wetted surfaces of the microfluidic channel.

5 . The diffusion-bonded product of claim 1 , wherein the two or more substantially compositionally similar metal sheets comprise substantially similar titanium alloys or titanium.

6 . The diffusion-bonded product of claim 5 , wherein a first sheet of the two or more substantially compositionally similar metal sheets comprises a commercially pure titanium sheet and a second sheet of the two or more substantially compositionally similar metal sheets comprises a sheet of a titanium 6AL-4V alloy.

7 . The diffusion-bonded product of claim 1 , wherein the two or more substantially compositionally similar metal sheets comprise austenitic stainless steels in AISI 300 series.

8 . The diffusion-bonded product of claim 1 , wherein the organic coating comprises a perfluorinated carbon compound.

9 . The diffusion-bonded product of claim 1 , wherein the organic coating comprises a hydrocarbon compound.

10 . The diffusion-bonded product of claim 1 , wherein the organic coating comprises an organic material having a desired hydrophobicity or hydrophilicity.

11 . A microfluidic device for separating a sample by chromatography, the microfluidic device comprising:
diffusion bonded metallic sheets, each metallic sheet having a substantially similar composition, the diffusion bonded metallic sheets joined to create a hermetically sealed interface between each adjacent metallic sheet without the introduction of a secondary material and to enclose a separation channel within the diffusion bonded metallic sheets accessible by at least one of an inlet or an outlet to the separation channel; wetted surfaces of the separation channel coated with an organic material at least one monolayer thick, and the separation channel packed with micrometer-sized particles serving as a stationary phase in a chromatographic separation.

12 . The device of claim 11 , wherein the diffusion bonded metallic sheets comprise substantially similar titanium alloys or titanium.

13 . The device of claim 12 , wherein a first sheet of the diffusion bonded metallic sheets comprises a commercially pure titanium sheet and a second sheet of the diffusion bonded metallic sheets, which is adjacent to the first sheet, comprises a sheet of a titanium 6AL-4V alloy.

14 . The device of claim 11 , wherein the diffusion bonded metallic sheets comprise austenitic stainless steels in AISI 300 series.

15 . The device of claim 11 , wherein an amorphous silicon material is deposited to be positioned between the wetted surfaces of the separation channel and the organic material.

16 . The device of claim 11 , wherein a deposited layer of inorganic-oxide is positioned between the wetted surfaces of the separation channel and the organic material.

17 . The device of claim 11 , wherein the organic material is hydrophobic.

18 . The device of claim 11 , wherein the organic material is hydrophilic.

19 . The device of claim 11 , wherein the diffusion bonded metallic sheets define an electrospray tip, the electrospray tip is in fluidic communication with the separation channel.

20 . The device of claim 11 , further comprising a particle retaining element in fluidic communication with the separation channel and positioned between the separation channel and the outlet to an exterior surface of the diffusion bonded metallic sheets.

21 . A method of manufacturing a microfluidic device for chromatographic separation of a sample; the method comprising:
patterning a first metallic sheet to define at least a portion of a fluidic channel by:
coating a surface of the first metallic sheet;
selectively removing one or more portions of the coating to expose one or more areas of the surface of the sheet;
at least partially immersing the first metallic sheet in an electrolyte; and
applying a voltage difference between the first metallic sheet and a cathode to selectively remove material from the one or more exposed areas by anodic dissolution to form the at least a portion of the fluidic channel within the first metallic sheet;
providing a second metallic sheet, the second metallic sheet having a composition substantially similar to the first metallic sheet; and diffusion bonding the first metallic sheet to the second metallic sheet to form a hermetically sealed interface having direct material contact of the first and second metallic sheets and to form and enclose the fluidic channel at least partially patterned in the first metallic sheet between the first and second metallic sheets at the interface.

22 . The method of claim 21 , wherein the coating is a polymeric photoresist.

23 . The method of claim 21 , wherein the coating is a titanium dioxide layer.

24 . The method of claim 22 , wherein the coating is selectively removed by a lithographic technique.

25 . The method of claim 23 , wherein the coating is selectively removed by a lithographic technique.

26 . The method of claim 25 , wherein the coating is selectively removed by a maskless lithographic technique.

27 . The method of claim 21 , further comprising:
coating a wetted surface of the fluidic channel formed by diffusion bonding the first metallic sheet to the second metallic sheet with a material to provide surface modification of the fluidic channel.

28 . The method of claim 27 , wherein the material comprises at least in part an organic material.

29 . The method of claim 27 , wherein the material comprises at least in part an inorganic-oxide.

Assignees

• Waters Technologies Corp

Inventors

• Bunner Bernard
• Dourdeville Theodore A

Classifications

• H01J49/167

  Capillaries and nozzles specially adapted therefor; (electrostatic spraying per se B05B5/00) · CPC title

• H01J49/0018

  Microminiaturised spectrometers, e.g. chip-integrated devices, Micro-Electro-Mechanical Systems [MEMS] · CPC title

• G01N30/7266 Primary

  by electric field, e.g. electrospray · CPC title

• G01N30/6095

  Micromachined or nanomachined, e.g. micro- or nanosize · CPC title

• B23K20/023

  Thermo-compression bonding · CPC title