Stress Induced Voltage Fluctuation for Measuring Stress and Strain in Materials

Category: Engineering and Physical Sciences

Reference Number: 00171

Description

The invention represents a novel electronic technique that detects stress/strain in a wide variety of conductive and semi-conductive materials. The technique may be used with a strain gauge or by making measurements directly in the material or component of interest. The technique is based on passing a current through the material of interest and analyzing the voltage noise spectra. A new type of electronic signal was observed while monitoring the fluctuations in sample voltage when the sample was put under stress/strain. The stress induced electronic signal was found to have characteristic spectra that is very sensitive to the amount of stress in the sample. The technique is suitable for sensitive measurements without a strain gauge. The technique is not limited by sample size, and provides a simple and fast, nondestructive and on-site evaluation of stress/strain in a material.

Applications

• The phenomena has immediate application for building very sensitive stress sensors, strain gauges with or without the help of a strain gauge.
• Determination of stress and strain in thin films used in the semiconductor and integrated circuit industries.
• Determination of stress and strain in materials and components used in the aviation, marine, military, and industrial sectors where stress is a factor in failure mode.

Main Advantages

• The invention is extremely sensitive, increasing the gauge factor of a typical strain gage of two to over one hundred and more.
• The invention allows for a wider range of stress detection, including levels above the yield point.
• The invention overcomes the required installation of strain gauges as part of the initial assembly or by difficult retrofits.
• The invention overcomes the need to obtain zero stress level conditions in the sample prior to mounting or retrofit.
• The technique is simple, versatile, portable, economical, fast, sensitive and non-destructive to the material and is not limited by sample size or complexity.

Inventor(s)

Dr. Anupam Misra
Dr. James R. Gaines
Dr. Richard Rocheleau
Dr. Steven Song
Hawaii Natural Energy Institute
Department of Physics and Astronomy

Contact Information

For licensing information, please contact Dick Cox at rcox@hawaii.edu

For all other inquiries, please write to:

Office of Technology Transfer & Economic Development
University of Hawai’i
2800 Woodlawn Drive, Suite 280
Honolulu, HI 96822