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Lightweight Fiber Optic Sensors for Real-Time Strain Monitoring

 

    › Benefits
    › Applications
    › Technology Details
    › Commercial Opportunity
    › Contact Information
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To improve efficiency and safety in aerospace, civil engineering, transportation, oil and gas, renewable energy, and medicine


Innovators at NASA’s Dryden Flight Research Center have developed a lightweight, robust fiber optic sensor system that represents a major breakthrough in sensing technology. The sensors, along with NASA’s sophisticated algorithms, can be used to calculate a variety of critical parameters including shape, stress, temperature, pressure, strength, and operational load. This state-of-the-art sensor system is small, lightweight, easy to install, and fast—it processes information at rates of 100 times per second. For the first time ever, real-time strain measurements can be used to determine the shape of an aircraft’s wing, monitor the structural integrity of bridges and pipelines, or ensure precise placement of the tiniest catheters, to name just a few potential applications.

Benefits

  • High resolution: Enables thousands of sensors to be placed at half-inch intervals for more comprehensive imaging than previously possible
  • Fast: Provides a 100-Hz refresh rate to enable real-time strain monitoring
  • Small and lightweight: Uses virtually weightless sensors and hardware the size of a shoebox
  • Comprehensive data: Calculates shape, stress, temperature, pressure, strength, and operational load
  • Non-intrusive: Uses a monitoring fiber that does not affect performance
  • Easy to install: Installs more quickly than conventional strain gauges and in regions previously inaccessible
  • Robust: Resists radiation and electromagnetic radio frequency interference

Applications

  • Aerospace: Sensing shape and structural health monitoring
  • Medical: Monitoring medical robotics, catheters, MRI machines, and radioactive environments
  • Renewable wind energy: Monitoring wind turbine blade deformation
  • Civil structures: Designing and monitoring bridges, tunnels, buildings, and dams
  • Automotive: Monitoring frame stress for improved safety and performance
  • Transportation and Rail: Monitoring integrity of train and tracks
  • Marine: Monitoring oil tankers, navy vessels, competitive yachts, and submarine hulls
  • Oil and Gas: Detecting leaks, monitoring pipelines, and downhole drilling
  • Power: Monitoring nuclear power plant vibration and temperature
  • Seismology: Monitoring shifts in the earth’s crust
  • Mining: Monitoring integrity of shafts
  • Military: Detecting chemical or biological agents

Technology Details

How It Works

The technology employs ultra-efficient, real-time, data driven algorithms for interpreting strain data. The fiber Bragg grating sensors respond to strain due to stress or pressure on the substrate. The fiber may also be covered with a “smart coating” that detects strain based on temperature, the presence of chemicals, and other factors. The sensors feed these strain measurements into the system’s algorithms to determine shape, stress, temperature, pressure, strength, and operational load in real time.

Why It Is Better

Conventional strain gauges are heavy, bulky, spaced at distant intervals (which leads to lower resolution imaging), and unable to provide real-time measurements. Dryden’s system is virtually weightless, and thousands of sensors can be placed at half-inch intervals along an optical fiber the size of a human hair. Because these sensors can be placed at such close intervals and in previously inaccessible regions (e.g., within bolted joints, embedded in a composite structure), the high-resolution strain measurements are much more precise than ever before. The fiber optic sensors are non-intrusive and easy to install—thousands of sensors can be installed in less time than conventional strain sensors—and the system is capable of processing information at the unprecedented rate of 100 samples per second. This critical, real-time monitoring capability enables an immediate and informed response in the event of an emergency and allows for precise, controlled monitoring to help avoid such scenarios.

Patents

Dryden has two patents issued (U.S. Patent No: 7,520,176→  and U.S. Patent No: 7,715,994→ ) and two others are pending for this technology.

Additional Information

Commercial Opportunity

Licensing this technology is available through the NASA Innovative Partnerships Office, which seeks to transfer technology into and out of NASA to benefit the space program and U.S. industry. NASA invites companies to consider partnering with NASA or licensing this Intrinsic Fiber Optic Sensor Portfolio (DRC-006-024, DRC-008-023, DRC-006-045, DRC-007-001, and DRC-009-013) for commercial applications.

Contact Information

Julie Holland
PO Box 273, M/S 1100
NASA’s Dryden Flight Research Center
Edwards, CA 93523-0273
Phone: (661) 276-2515
E-mail: julie.a.holland@nasa.gov