Method of fabricating microfluidic systems

• US 8,852,526 B2
• Filed: 07/10/2009
• Issued: 10/07/2014
• 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
• Primary Examiner(s): Sines, Brian J
• Application Number:
  US13/003,647
• Publication Number:
  US 20120009662A1
• Time in Patent Office: 1,915 Days
• Field of Search: 422/68.1, 422/502, 422/503, 422/507
• US Class Current: 422/503
• 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 flexible microfluidic device having microfluidic channels on a surface of a flexible hydrophilic substrate formed of cellulosic material, the method including the steps of:

(a) hydrophobizing the flexible hydrophilic substrate surface by absorbing or adsorbing a hydrophobic substance on or within the substrate;

(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 while retaining flexibility of the flexible hydrophilic substrate.

2. 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.

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

4. A microfluidic device, said device comprising microfluidic channels, wherein the microfluidic channels of the device are positioned on a flexible portion of a cellulosic substrate, said device fabricated by the method according to claim 1.

5. The method of claim 1 wherein the cellulosic material comprises paper, a woven cellulosic material, or a non-woven cellulosic material.

6. The method of claim 1, wherein the flexible hydrophilic substrate comprises a porous material.

7. The microfluidic device according to claim 4, 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.

8. The microfluidic device according to claim 4 wherein the irradiation treatment includes plasma and corona treatments.

9. The microfluidic device according to claim 4, wherein the cellulosic material comprises a porous material.

10. The microfluidic device according to claim 4, wherein the cellulosic material comprises paper, a woven cellulosic material, or a non-woven cellulosic material.