# Presentation: 797565

## Methods for Polymer Microfluidic Fabrication

**Methods for Polymer Microfluidic Fabrication**

- David Ross, Physicist
- NIST
- Gaithersburg, MD

## Polymers for microfluidics
Single-use, disposable
Point-of-care diagnostics
Forensics
In microfluidics, the surface is everything
Sample adsorption
Wetting
Fluid flow
Problem: Polymer surfaces not well controlled

- Single-use, disposable
- Point-of-care diagnostics
- Forensics
- In microfluidics, the surface is everything
- Sample adsorption
- Wetting
- Fluid flow
- Problem: Polymer surfaces not well controlled

**Technology Summary**

**Notes:**
Conventional surface modification methods don’t work well with polymers

## Our technologies: tools for microfluidic polymer fabrication
General-use surface coatings
One step channel fabrication and surface modification
Laser modification of preformed microchannels

- General-use surface coatings
- One step channel fabrication and surface modification
- Laser modification of preformed microchannels

**Technology Description**

**Notes:**
Three methods for fabrication and control of polymer microfluidic surfaces

## Conventional Plastic Fabrication

**Conventional Plastic Fabrication**

**heater**

**heater**

**plastic substrate**

**template**

**apply pressure**

**Notes:**
Most common polymer device fabrication method: hot embossing/imprinting

## Polyelectrolyte Multilayer Coatings (PEMS)

**Polyelectrolyte Multilayer Coatings (PEMS)**

**Alternating layers of charged polymers**
**Easy, inexpensive**
**Insensitive to substrate material**

**Notes:**
Much easier than covalent surface modification
Can choose polymer for mechanical properties and use PEMS for surface properties

## What is Photoablation?

**Pulsed UV Laser**

**Focusing**
**optics**

**programmable motion stage**

**microchannel**

**plastic**

**Notes:**
Fabrication and surface modification in one step
Can pattern different areas by changing process gas during ablation

## Photomodification of preformed microchannel

**Photomodification of preformed microchannel**

**Pulsed UV Laser**

**Focusing**
**optics**

**Notes:**
Can be used to modify portions of embossed or imprinted channels
Modified areas can be controlled with high spatial resolution

## Photomodification for microarrays within channels

- Protein microarrays within microchannel

**Notes:**
Laser modification used to immobilize proteins at selected sites within a microchannel

## Photopatterning for flow control

- UV Laser

- Hydrophilic-Hydrophobic Valve

**Notes:**
Used to control wetting properties of polymer substrate for valving

## Technical Challenge: Scale-up
Intellectual property: 3 Patents issued (U.S. 6,703,189, 6,860,980, 6,982,028)
Ready for Licensing
Competitors / substitutes
Covalent chemical modification

- Intellectual property: 3 Patents issued (U.S. 6,703,189, 6,860,980, 6,982,028)
- Ready for Licensing
- Competitors / substitutes
- Covalent chemical modification

**Current Status**

## Contact

- For more information:
- David Ross
- National Institute of Standards and Technology
- 301-975-2525
- david.ross@nist.gov
- Laurie Locascio
- National Institute of Standards and Technology
- 301-975-3130
- laurie.locascio@nist.gov

**Notes:**
Instructions on whom to contact.