Optical fibers in materials: an artificial nervous system

Aug 29, 2012 by Sarah Perrin
Optical fibers in materials: an artificial nervous system
When placed inside a material, optical fibers act like artificial nerves, transmitting valuable information about a structure’s state of fatigue and wear. A new technique developed at EPFL makes it possible to collect this data with vastly improved resolution and efficiency, opening up the possibility of new applications, particularly in much smaller objects.

(Phys.org)—When placed inside a material, optical fibers act like artificial nerves, transmitting valuable information about a structure's state of fatigue and wear. A new technique developed at EPFL makes it possible to collect this data with vastly improved resolution and efficiency, opening up the possibility of new applications, particularly in much smaller objects.

What if one day our cars or vacuum cleaners could warn us when they're on the verge of wearing out? EPFL's Group for (GFO) has just made an important step in this direction. In the context of monitoring infrastructures such as bridges, dams and buildings, the GFO has developed a technology that improves the resolution of measurements taken by optical fibers embedded in these structures. This discovery, recently published in the journal Laser & Photonics Reviews, opens up possible new applications for optical fibers, particularly in smaller objects.

Up to this point, data could be collected from points about one meter apart using optical fibers, thin glass threads embedded in the concrete of a construction. But now, can be taken as much as every centimeter – a hundredfold improvement in precision. "Right now, we're mainly measuring changes in temperature and force, but this method should eventually also make it possible to measure pressure variations, or even variations in magnetic field," predicts GFO director Luc Thévenaz.

With this improvement, the fiber can act as a true artificial . It would be able to signal the presence of "hot spots", weaknesses, deformations or liquid or gas leakages much more reliably, significantly improving our ability to monitor large infrastructures.

Follow the vibration…

Placed in certain environments, such as underground, this method provides a means of detecting terrain movements or preventing the malfunction of geothermal energy installations. Placed in a glacier, it could provide information on the evolution of the snow pack. Joint research with EPFL's Environmental Fluid Mechanics Laboratory (EFLUM) has been initiated with this objective in mind.

Above all, this new technology makes it possible to use optical fibers in smaller objects, such as robots, household appliances, or skis. It has been proposed to ride aboard the arms of a new project underway in EPFL's Space Center, "Clean Space One," a small satellite designed for cleaning up space debris floating in near Earth orbit.

From a practical viewpoint, the system puts the fiber into "resonance" by sending, via laser, a beam of light to each end of the fiber. These waves of light generate acoustic vibrations, whose pitch change as a function of temperature. Thus the vibrations reveal valuable information about the temperature in the area surrounding the fiber. By recording the data, the scientists can locate hot spots or unusual forces. "The advantage of this technique," says Thévenaz, "is that it allows us to collect data at a very precise, pre-determined point."

Explore further: Engineers find a way to win in laser performance by losing

Related Stories

Researchers make optical fibers from common materials

Aug 13, 2012

Clemson researchers are taking common materials to uncommon places by transforming easily obtainable and affordable materials into fiber. Their findings are published in Nature Photonics, the world's top jo ...

Recommended for you

1980s aircraft helps quantum technology take flight

1 hour ago

What does a 1980s experimental aircraft have to do with state-of-the art quantum technology? Lots, as shown by new research from the Quantum Control Laboratory at the University of Sydney, and published in Nature Physics today. ...

Atomic trigger shatters mystery of how glass deforms

Oct 18, 2014

Throw a rock through a window made of silica glass, and the brittle, insulating oxide pane shatters. But whack a golf ball with a club made of metallic glass—a resilient conductor that looks like metal—and the glass not ...

Superconducting circuits, simplified

Oct 17, 2014

Computer chips with superconducting circuits—circuits with zero electrical resistance—would be 50 to 100 times as energy-efficient as today's chips, an attractive trait given the increasing power consumption ...

Protons hog the momentum in neutron-rich nuclei

Oct 16, 2014

Like dancers swirling on the dance floor with bystanders looking on, protons and neutrons that have briefly paired up in the nucleus have higher-average momentum, leaving less for non-paired nucleons. Using ...

User comments : 0