A Safer, Cheaper Way to Track Defects in Aircraft Structures


It’s important for engineers to closely monitor the safety and durability of the composite materials used in aircraft and spacecraft, which are subject to myriad physical stresses. An aircraft flying at 30,000 feet or a spacecraft in orbit are, however, not the best places for electric sensors, which hold the potential for sparking and causing fires.

A fiber-optic sensor, such as the one developed by Nikhil Gupta of the Department of Mechanical and Aerospace Engineering at the NYU Polytechnic School of Engineering, provides a much safer alternative. The patented extensometer is also exceptionally sensitive, able to detect a single micron in displacement. (The extensometer is so called because it measures the extension of a material: Picture a piece of rope being stretched and the elongation of its fibers calculated.)

Earlier this year Gupta earned a second patent—this one for a method of using his device, which works by sending out a beam of light and measuring how much passes through the material being tested. The presence or growth of defects changes the intensity of light passing through the system, which is detected by the sensor.

While many current sensors with their instrumentation systems range from $10,000 to $50,000, Gupta’s sensor system will cost less than $1,000—a price that will allow it to be deployed widely, with a greater variety of applications that may reach far beyond the aerospace industry.