Original Date: 11/03/1996
Revision Date: 01/18/2007

Oak Ridge Centers for Manufacturing Technology (ORCMT) has been using a new class of optical fibers called silicone rubber fiber optics (SRFO) in many sensor development programs. Fabricated from a silicone elastomer, SRFO features a remarkable elasticity (Figure 3-7). This elasticity allows SRFO to be tied into knots, stretched to twice its original length, or compressed from its normal circular profile into an ellipse. After enduring such deformations, SRFO sustains no permanent damage and will return to its original shape and size. Standard optical fibers use relatively inflexible materials such as glass or plastic which will usually break when stretched.

As expected, SRFO’s transmission characteristics will vary whenever the fiber is subjected to moisture, elongation, compression, or displacement. This feature enables SRFO to be used for monitoring static and dynamic pressure, moisture, relative humidity, force, weight, strain, and other physical parameters. SRFO can also transmit more optical power than standard optical fibers which makes it ideal for systems that require small, rugged, and relatively inexpensive sensors.

ORCMT has been developing various SRFO sensing systems such as a portable weighing device for vehicles in motion, an on-line vehicle counter, a self-weighing trailer, and miniature pressure sensors. In some applications, the SRFO sensing systems consistently met or exceeded the reliability standards of conventional sensing systems, and are less prone to oscillatory ringing. Possible applications include embedding SRFO sensors into carpets for security systems; into concrete for measuring crack formation, strain, or curing; and into orthopedic devices for monitoring rehabilitation or sports training.

For more information see the Point of Contact for this survey.