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An Environmentally Safe Detector for Hazardous Gas

Oak Ridge National Laboratory

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Technology Marketing Summary

ORNL researchers developed a breakthrough design for a hazardous-gas detector
that is environmentally safe and inexpensive and that includes both sensing and
detecting means. The invention can detect and identify volatile organic and inorganic
substances in vapors faster than conventional methods. Improved sensitivity using less
complicated, less expensive measuring devices is another key feature of this invention.
The core of this invention is based on observations that when an ionic liquid is exposed
to an environment containing a volatile substance, the ionic liquid dissolves some of
the volatile substance. The substance then adsorbs on the surface of carbon electrodes
and alters the energy of the electrochemical capacitor where the ionic liquid is the


Unlike dielectric capacitance-based gas detectors, this invention uses ionic liquids as
the means of sensing. The use of ionic liquids permits a much higher energy storage
capacity than those devices using polymers. The energy variances caused by the
changes in ionic liquids’ properties are generally larger than those caused using
polymers. As a result, this invention can attain higher sensitivity using less complex and
less costly measuring devices.

  • Environmentally friendly, by incorporating ionic liquids the use of pollutants is avoided
  • Easily miniaturized, even to the degree that it can be mounted on a printed circuit board
  • Improved sensitivity, largely due to greater capacitance variances
  • Less expensive and a much simpler measuring device

Applications and Industries
  • Potential Applications
  • Industry and research laboratories
  • Field studies

More Information

Shannon M. Mahurin, Sheng Dai, and Josip Caja, Method and Apparatus for Detection of Chemical Vapors, U.S. Patent US 7,217,354, issued May 15, 2007.

Lead Inventor
Shannon Mark Mahurin
Chemical Sciences Division
Oak Ridge National Laboratory

Patents and Patent Applications
ID Number
Title and Abstract
Primary Lab
Patent 7,217,354
Method and apparatus for detection of chemical vapors
The present invention is a gas detector and method for using the gas detector for detecting and identifying volatile organic and/or volatile inorganic substances present in unknown vapors in an environment. The gas detector comprises a sensing means and a detecting means for detecting electrical capacitance variance of the sensing means and for further identifying the volatile organic and volatile inorganic substances. The sensing means comprises at least one sensing unit and a sensing material allocated therein the sensing unit. The sensing material is an ionic liquid which is exposed to the environment and is capable of dissolving a quantity of said volatile substance upon exposure thereto. The sensing means constitutes an electrochemical capacitor and the detecting means is in electrical communication with the sensing means.
Oak Ridge National Laboratory 05/15/2007
Technology Status
Technology IDDevelopment StageAvailabilityPublishedLast Updated

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To: Jennifer Tonzello Caldwell, Ph.D.<>