METHOD OF FABRICATING MICROFLUIDIC SYSTEMS

• US 20120009662A1
• Filed: 07/10/2009
• Published: 01/12/2012
• Est. Priority Date: 07/11/2008
• Status: Active Grant

• Current Assignee: Monash University
• Original Assignee: Monash University
• Inventors: Shen, Wei, Li, Xu, Tian, Junfei, Khan, Mohidus Samad, Garnier, Gil
• Granted Patent: US 8,852,526 B2
• Time in Patent Office: Days
• US Class Current: 435/283.1
• CPC Class Codes: B01L 2200/10 Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2300/126 Paper
• CPC Class Codes: B01L 2300/161 Control and use of surface tension forces, e.g. hydrophobic, hydrophilic
• CPC Class Codes: B01L 3/502707 characterised by the manufacture of the container or its components by shaping or joining plastic parts B29C59/00, B29C65/00; by laminating B32B37/00; manufacture of microstructural devices in general B81C
• CPC Class Codes: D21H 17/16 Addition products thereof with hydrocarbons
• CPC Class Codes: D21H 17/17 Ketenes, e.g. ketene dimers
• CPC Class Codes: D21H 19/10 Coatings without pigments D21H19/66 takes precedence
• CPC Class Codes: D21H 21/16 Sizing or water-repelling agents
• CPC Class Codes: Y10T 436/11 Automated chemical analysis

Abstract

A method of fabricating a microfluidic system having microfluidic channels on a surface of a hydrophilic substrate, the method including the steps of: hydrophobizing the substrate surface; locating a mask defining the substrate surface, the mask having open areas defining the periphery of the microfluidic channels; and applying an irradiation treatment to areas of the substrate surface exposed by the open areas of the mask, said exposed areas becoming hydrophilic to therefore form said microfluidic channels.

Claims

1. A method of fabricating a microfluidic system having microfluidic channels on a surface of a hydrophilic substrate, the method including the steps of:

(a) hydrophobizing the substrate surface;

(b) locating a mask defining the substrate surface, the mask having open areas defining the periphery of the microfluidic channels; and

(c) applying an irradiation treatment to areas of the substrate surface exposed by the open areas of the mask, said exposed areas becoming hydrophilic to therefore form said microfluidic channels.

2. The method according to claim 1, wherein the hydrophilic substrate is formed of cellulosic material.

3. The method according to claim 1, wherein the surface is hydrophobized using a solution including a hydrophobic substance dissolved in a volatile solvent, the hydrophobic substance being selected from an alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), rosin, latex, silicones, fluorochemicals, polyolefin emulsions, resin and fatty acids, natural and synthetic waxes.

4. The method according to claim 1 wherein the irradiation treatment includes plasma and corona treatments.

5. A microfluidic system fabricated by the method according to claim 1.

16. The method of claim 2 wherein the cellulosic material comprises paper, a woven cellulosic material, or a non-woven cellulosic material.

6. A method of fabricating a microfluidic system having microfluidic channels on a surface of a hydrophilic substrate, the method including the step of printing a hydrophobic agent on the substrate surface to thereby provide a hydrophilic-hydrophobic contrast thereon to define a peripheral edge of the microfluidic channels.

7. The method according to claim 6 wherein the hydrophobic agent is a hydrophobic molecule, oligomer or polymer dissolved in a solvent.

8. The method according to claim 6 wherein the hydrophobic agent is a hydrophobic molecule, oligomer or polymer emulsified or in suspension in water, forming a water based ink.

9. The method according to claim 6 wherein the hydrophobic agent is an internal size (AKD, ASA, rosin, silicone, fluorochemicals, polyolefin emulsions, resin and fatty acid, natural and synthetic waxes and the like) or a surface sizing material (Styrene maleic anhydride (SMA), latex).

10. The method according to claim 9, wherein the hydrophobic agent is dissolved in an organic solvent or emulsified.

11. The method according to claim 6 further including an activation step following printing to activate the hydrophobic agent, including the development of covalent bond with the substrate.

12. The method according to claim 11 wherein the activation step includes aging, heat treatment or radiation.

13. The method according to any one of claims 6 to 12, wherein the hydrophilic substrate is formed of cellulosic material including paper, woven and non-woven materials.

14. The method according to claim 13 wherein the printing is by an inkjet or other contact and non-contact process printing applications.

15. A microfluidic system fabricated by the method as claimed in claim 6.