Microfluidic devices and methods for manufacturing microfluidic devices

Patent metadata

Field	Value
Publication number	US-11752500-B2
Application number	US-201917049676-A
Country	US
Kind code	B2
Filing date	Apr 23, 2019
Priority date	Apr 27, 2018
Publication date	Sep 12, 2023
Grant date	Sep 12, 2023

Abstract

A method for manufacturing a microfluidic device (100) includes depositing a bonding layer (106) on a surface of a second glass layer (104a) of a glass substrate having a first glass layer (102) and the second glass layer (104a) fused to the first glass layer (102), such that a masked region of the surface is covered by the bonding layer, and an exposed region of the surface is uncovered by the bonding layer; removing a portion of the second glass layer corresponding to the exposed region of the surface to form a flow channel (112) in the glass substrate; and bonding a cover (108) to the glass substrate with the bonding layer (106).

First claim

What is claimed is:

1. A microfluidic device comprising:
a glass-based substrate comprising a first glass-based layer and a second glass-based layer fused to the first glass-based layer;
a flow channel disposed in the glass-based substrate, the flow channel derived from exposure of the glass-based substrate to an acid- and surfactant-containing etchant; and
a cover bonded to the second glass-based layer and at least partially covering the flow channel;
wherein a floor of the flow channel has an average surface flatness of at most about 100 nm/mm, as measured in a longitudinal direction at a central portion of a flow channel of a test sample with a laser interferometer and calculated from flatness data obtained from at least three respective flow channels of at least three separately formed test samples, each test sample being materially the same as the microfluidic device,
wherein the first glass-based layer defines the floor of the flow channel, the second glass-based layer defines sidewalls of the flow channel and the cover defines a ceiling of the flow channel,
wherein the second glass-based layer comprises an etch rate in the etchant that is higher than an etch rate of the first glass-based layer in the etchant, and
further wherein the second glass-based layer has a composition comprising SiO 2 from 45 to 60 mol %, Al 2 O 3 from 8 to 19 mol %, B 2 O 3 from 5 to 23 mol %, and Na 2 O from 3 to 21 mol % and the first glass-based layer has a composition with more SiO 2 than the SiO 2 in the composition of the second glass-based layer.

2. The microfluidic device of claim 1 , comprising:
an inlet opening through at least one of the glass-based substrate or the cover and in fluid communication with the flow channel; and
an outlet opening through at least one of the glass-based substrate or the cover and in fluid communication with the flow channel.

3. The microfluidic device of claim 1 , wherein the floor of the flow channel has a surface flatness variance of at most about 3 μm along a length of the flow channel, as measured at a central portion of the flow channel.

4. The microfluidic device of claim 1 , wherein the floor of the channel has a surface roughness (Ra) of at most about 10 nm, as measured according to ISO 25178, Geometric Product Specifications, with a laser interferometer.

5. The microfluidic device of claim 1 , comprising a bonding layer disposed between the first glass-based layer and the cover, wherein the cover is bonded to the second glass-based layer at a bonded volume comprising the bonding layer diffused into each of the second glass-based layer and the cover.

6. The microfluidic device of claim 5 , wherein the bonding layer comprises a metal.

7. The microfluidic device of claim 5 , wherein the bonding layer comprises a polymer-carbon black composite film.

8. The microfluidic device of claim 1 , wherein a length of the channel is at least about 10 mm.

9. The microfluidic device of claim 1 , wherein an interface between the first glass-based layer and the second glass-based layer of the glass-based substrate is a glass-glass interface that is free of bonding material.

10. A microfluidic device comprising:
a glass-based substrate comprising a first glass-based layer and a second glass-based layer fused to the first glass-based layer;
a flow channel disposed in the glass-based substrate, the flow channel derived from exposure of the glass-based substrate to an acid- and surfactant-containing etchant; and
a cover bonded to the second glass-based layer and at least partially covering the flow channel,
wherein a floor of the flow channel has an average surface flatness of at most about 100 nm/mm, as measured in a longitudinal direction at a central portion of a flow channel of a test sample with a laser interferometer and calculated from flatness data obtained from at least three respective flow channels of at least three separately formed test samples, each test sample being materially the same as the microfluidic device,
wherein the first glass-based layer defines the floor of the flow channel, the second glass-based layer defines sidewalls of the flow channel and the cover defines a ceiling of the flow channel,
wherein the second glass-based layer comprises an etch rate in the etchant that is higher than an etch rate of the first glass-based layer in the etchant, and
further wherein the second glass-based layer has a composition comprising SiO 2 from 45 to 60 mol %, Al 2 O 3 from 8 to 19 mol %, B 2 O 3 from 5 to 23 mol %, and Na 2 O from 3 to 21 mol % and the first glass-based layer comprises a boro-aluminosilicate glass composition.

11. A microfluidic device comprising:
a glass-based substrate comprising a first glass-based layer and a second glass-based layer fused to the first glass-based layer;
a flow channel disposed in the glass-based substrate, the flow channel derived from exposure of the glass-based substrate to an acid- and surfactant-containing etchant; and
a cover bonded to the second glass-based layer and at least partially covering the flow channel,
wherein a floor of the flow channel has an average surface flatness of at most about 100 nm/mm, as measured and averaged in a longitudinal direction (Y-direction) at a central portion of the flow channel,
wherein the floor of the flow channel has an average surface flatness of at most about −30 nm/mm, as measured and averaged in a lateral direction (X-direction) at a central portion of the flow channel,
wherein the first glass-based layer defines the floor of the flow channel, the second glass-based layer defines sidewalls of the flow channel and the cover defines a ceiling of the flow channel,
wherein the second glass-based layer comprises an etch rate in the etchant that is higher than an etch rate of the first glass-based layer in the etchant, and
further wherein the second glass-based layer has a composition comprising SiO 2 from 45 to 60 mol %, Al 2 O 3 from 8 to 19 mol %, B 2 O 3 from 5 to 23 mol %, and Na 2 O from 3 to 21 mol % and the first glass-based layer comprises a boro-aluminosilicate glass composition.

Assignees

• Corning Inc

Inventors

• Fang Ye
• Kim Jin Su
• Li Aize

Classifications

• B01L3/502707 Primary

  characterised by the manufacture of the container or its components · CPC title

• B01L3/502715 Primary

  characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces · CPC title

• B01L2200/12

  Specific details about manufacturing devices · CPC title

• B01L2300/12

  Specific details about materials · CPC title

• C03C15/02

  for making a smooth surface · CPC title