Viscosity-mismatched fluid waveguide aimed at biomedical research

June 1, 2006
Using carefully tailored fluid flow, researchers at the Colorado School of Mines are creating all-fluid optical waveguides (contained on a solid substrate) composed of two liquids with mismatched viscosity.

Using carefully tailored fluid flow, researchers at the Colorado School of Mines are creating all-fluid optical waveguides (contained on a solid substrate) composed of two liquids with mismatched viscosity. The waveguides are potentially useful in dynamically switched microfluidic-based analytical systems for biomedical research. The more-viscous core, a 67%-by-weight sucrose/water solution, has a refractive index of 1.457, while the pure-water cladding has an index of 1.33. Two flows of cladding squeeze the central core to provide a taper that ends in a core width of about 15 µm.

The core/cladding boundary is smooth due to laminar flow. Over the length of the waveguide, the boundary becomes graded because of diffusion-a phenomenon that can be tailored based on flow such that step-index, graded-index, multimode, or single-mode waveguides are possible. The researchers demonstrated fluorescence detection and emission collection in a fluid waveguide that carried fluorescent colloids in its core, which was pumped with 632 nm light (the waveguide flowed up against and was diverted by a transparent wall, through which the emission was detected). Contact David Marr at [email protected].

Sponsored Recommendations

Advancing Neuroscience Using High-Precision 3D Printing

March 7, 2025
Learn how Cold Spring Harbor Laboratory Used High-Precision 3D Printing to Advance Neuroscience Research using 3D Printed Optical Drives.

From Prototyping to Production: How High-Precision 3D Printing is Reinventing Electronics Manufacturing

March 7, 2025
Learn how micro 3D printing is enabling miniaturization. As products get smaller the challenge to manufacture small parts increases.

Sputtered Thin-film Coatings

Feb. 27, 2025
Optical thin-film coatings can be deposited by a variety of methods. Learn about 2 traditional methods and a deposition process called sputtering.

What are Notch Filters?

Feb. 27, 2025
Notch filters are ideal for applications that require nearly complete rejection of a laser line while passing as much non-laser light as possible.

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!