01-8767. Government Owned Inventions Available for Licensing

AGENCY:

National Institute of Standards and Technology, Commerce.

ACTION:

Notice of Government Owned Inventions Available for Licensing.

SUMMARY:

The inventions listed below are owned in whole or in part by the U.S. Government, as represented by the Department of Commerce. The Department of Commerce's interest in the inventions is available for licensing in accordance with 35 U.S.C. 207 and 37 CFR part 404 to achieve expeditious commercialization of results of federally funded research and development.

FOR FURTHER INFORMATION CONTACT:

Technical and licensing information on these inventions may be obtained by writing to: National Institute of Standards and Technology, Office of Technology Partnerships, Building 820, Room 213, Gaithersburg, MD 20899; Fax [phone]. Any request for information should include the NIST Docket No. and Title for the relevant invention as indicated below.

SUPPLEMENTARY INFORMATION:

NIST may enter into a Cooperative Research and Development Agreement (“CRADA”) with the licensee to perform further research on the inventions for purposes of commercialization. The inventions available for licensing are:

NIST Docket Number: 98-029US.

Title: Method And Apparatus For Bias And Readout Of Bolometers Operated On A Hysteretic Metal-Insulator Transition.

Abstract: This invention consists of a bias and readout scheme for resistive bolometers. It is chiefly intended for use with bolometer materials which exhibit a phase transition that is hysteretic. The most obvious example of such a bolometer material is vanadium dioxide, which has a metal-semiconductor phase transition at 68 degrees Celsius and a hysteresis of typically 5 degrees Celsius depending on material preparation. The existence of hysteresis precludes the use of a conventional DC bias or a conventional pulsed bias in a bolometer operated on the phase transition. In the technique we are disclosing, the bias consists of an AC current. (This is for phase transitions in which the resistance decreases with increasing temperature. For phase transitions in which the resistance increases with temperature, an AC voltage bias would be used.) The waveform of the AC bias consists of a short “reset” segment, in which the peak current is high enough to bring the bolometer completely into its metallic state, followed by a longer “data” segment, in which the bias current and bias power monotonically decrease, so as to sweep the bolometer's physical temperature downward across the phase transition. The frequency of the AC bias is determined by the condition that the slew rate in bias power during the data segment must always exceed the slew rate in signal power, for all signals of interest. The signal is read out by averaging the bolometer voltage over a time window lying entirely within the data segment. With this bias and readout scheme, the full slope of the bolometer R(T) characteristic is reflected in the output from small signals, which would not be the case for a conventional DC or pulsed bias scheme. Since the full slope of the R(T) characteristic is accessible, the bolometer can operate in the extreme electrothermal feedback regime, which provides major improvements in speed 1/f-noise, and sensitivity.

Dated: April 3, 2001.

Karen H. Brown,

Acting Director.