Printer Friendly

Swell idea for a chemical sensor.

Swell idea for a chemical sensor

Many scientists want to perfect miniature chemical sensors to detect small quantities of drugs, pollutants, oxygen or other substances in the environment or the body. Yet after a decade's work, few such devices have reached the marketplace. Now, two chemists have patented their ideas for what they call a cheap technology with many applications. The secret of their device: a swellable polymer, says Marian F. McCurley of the National Institute of Standards and Technology in Gaithersburg, Md.

The new sensor contains two optical fibers, one to carry light down to the sensing tip and the other to carry the reflected light back out. The sensing tip consists of a polymer lens specially made to react to the substance being monitored. A reflective film coats one side of this lens.

When the polymer detects its target chemical, its cross-linkages change. Depending on the particular chemistry between the two materials, the polymer either expands to let water in or shrinks. As the lens changes shape, it pushes the reflective film closer to or farther from the optical fibers, thereby changing the amount of reflected light.

Unlike most biosensors, this one isolates the light from the chemical components, and that means the system should last longer, says Kenneth D. Legg, president of Polysense, Inc., in Wellesley, Mass., which plans to develop the technology.
COPYRIGHT 1991 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1991, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:swelling polymers
Author:Pennisi, Elizabeth
Publication:Science News
Date:Apr 27, 1991
Words:226
Previous Article:Enhancing that fresh-squeezed flavor.
Next Article:Caterpillar bodies not built for speed.
Topics:


Related Articles
Compound variables affecting roll compounds exposed to service fluids.
Wiggly gel makes a muscle.
A new polymer system for tire innerliners.
Controlled alloying of CSM roofing membranes with thermoplastic resins.
Novel Luminescent Biosensor.
SMELLING IN COLOR: a RAINBOW OF POSSIBILITIES.
Comparing fuel and oil resistance properties.
Polymers on silicon chip catch, release proteins. (Tiny Labs).
Hole-wall pullaway and desmearing: further study of the causes of HWPA.
Characterization of a new type of bisphenol cured FKM.

Terms of use | Copyright © 2017 Farlex, Inc. | Feedback | For webmasters