Stop flow interference lithography system

• US 8,252,517 B2
• Filed: 07/16/2009
• Issued: 08/28/2012
• Est. Priority Date: 07/18/2008
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Thomas, Edwin L., Doyle, Patrick Seamus, Dendukuri, Dhananjay, Jang, Ji-Hyun, Ullal, Chaitanya K.
• Primary Examiner(s): McPherson, John A.
• Application Number:
  US12/503,935
• Publication Number:
  US 20100099048A1
• Time in Patent Office: 1,139 Days
• Field of Search: None
• US Class Current: 430/320
• CPC Class Codes: G03B 27/54 Lamp housings; Illuminating means
• CPC Class Codes: G03F 7/027 Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds G03F7/075 takes precedence
• CPC Class Codes: G03F 7/2012 using liquid photohardening compositions, e.g. for the production of reliefs such as flexographic plates or stamps
• CPC Class Codes: G03F 7/2035 simultaneous coating and exposure; using a belt mask, e.g. endless
• CPC Class Codes: G03F 7/40 Treatment after imagewise removal, e.g. baking

Abstract

Stop flow interference lithography system for high throughput synthesis of 3-dimensionally patterned polymer particles. The system includes a microfluidic channel containing a stationary oligomer film and a phase mask located adjacent to the microfluidic channel. A source of collimated light is provided for passing the collimated light through the phase mask and into the microfluidic channel for interaction with the oligomer. The passage of the collimated light through the phase mask generates a 3-dimensional distribution of light intensity to induce crosslinking of the oligomer in high intensity regions thereby forming 3-dimensional structures.

Claims

1. Stop flow interference lithography system for high throughput synthesis of 3-dimensionally patterned polymeric particles comprising:

a microfluidic channel configured to hold a stationary oligomer;

a phase mask located adjacent to the microfluidic channel; and

a source of collimated light for passing the collimated light through the phase mask and into the microfluidic channel for interaction with the oligomer, the passage of the collimated light through the phase mask generating a 3-dimensional distribution of light intensity to induce crosslinking of the oligomer in high intensity regions thereby forming 3-dimensional structures.

2. The system of claim 1 wherein the light source comprises a pulsed laser.

3. The system of claim 2 further including a shutter for regulating light from the light source.

4. The system of claim 1 wherein the light source comprises a mercury lamp.

5. The system of claim 1 further including a mask for transmitting light from the light source to define the 2-dimensional shape of the particles.

6. The system of claim 5 wherein the mask comprises a lithographic mask.

7. The system of claim 5 wherein the mask comprises a transparency mask.

8. The system of claim 5 wherein the mask comprises a chrome mask.

9. The system of claim 5 wherein the mask comprises a gray-scale mask.

10. The system of claim 1 wherein the oligomer includes a photoinitiator.

11. The system of claim 1 further including a protective layer between the phase mask and the liquid oligomer.

12. The system of claim 1 further including a radical inhibitor in the oligomer.

13. The system of claim 1 wherein the particles possess chemical anisotropy.

14. The system of claim 1 wherein the microchannel has a non-rectangular cross-section.

15. The system of claim 1 wherein the oligomer solution contains cells, viruses, proteins, nanoparticles, microparticles or other small entities.

16. The system of claim 1 wherein the oligomer solution contains a porogen.

17. The system of claim 1 wherein the high intensity regions polymerize the microstructure by thermal polymerization.

18. The system of claim 1 further comprising a digital micromirror device configured to control shape of the collimated light.

19. The system of claim 1 wherein the source of collimated light is configured to change shape of the collimated light dynamically while passing the collimated light through the phase mask.

20. A method for high throughput synthesis of 3-dimensionally patterned polymeric particle comprising:

causing an oligomer to become stationary in the microfluidic channel of the stop flow interference lithography system of claim 1; and

generating a 3-dimensional distribution of light intensity in the microfluidic channel to induce crosslinking of the oligomer in high intensity regions of the 3-dimensional distribution in the microfluidic channel thereby forming a 3-dimensional structure.