Jan. 30 (UPI) -- Using the unique ultrasound system deployed by bats as inspiration, engineers have developed a new way to locate corroding metal in oil and gas pipelines.
To hunt prey and dodge objects while flying through the air, usually in the dark, bats use a combination of different ultrasound wavelengths. The new corrosion detection system uses two different kinds of radiation, fast neutrons and gamma rays.
Ultrasonic or electromagnetic methods are typically used for finding corrosion in pipes, but the techniques don't work for underground pipes or pipes with concrete or plastic insulation. The new system works on all kinds of metal and composite pipes.
To locate corrosion, the system sends out the two radiation types and records the electrical signal they produce. The combination of electrical signals, called the backscatter, can be simultaneously recorded by the system's sensor.
The two radiation types complement each other. Neutrons interact with low-density materials like plastics and are capable of penetrating deep through different layers of material. Gamma rays interact with metals but can't penetrate as well.
When scientists tested the new technique on carbon-steel samples in the lab, the electrical signals produced by the radiation successfully revealed the varying thickness in each sample.
"The combined beams of neutrons and gamma rays in parallel bouncing back to an array of detectors yield a comprehensive and fast representation of the inner structure of steel," lead researcher Mauro Licata, a doctoral student in engineering at Lancaster University in Britain, said in a news release.
The addition of an insulating layer of concrete or plastic didn't interfere with the system's ability to image thickness.
"This system works a bit like the chirps made by bats. These chirps are a superposition of different ultrasound wavelengths, which bounce back to the bats' ears," Licata said. "As well as highlighting the benefits of combining multiple reflection sensing techniques to detect for problems such as corrosion, our work further illustrates the significant potential that can be had from taking inspiration from, and mimicking, systems that have evolved in the natural world."
Scientists described the new technology in a paper published Thursday in the journal Scientific Reports. The research team is now working to make the backscatter sensor work faster.
According to the study authors, the sensing device could also be used to detect structural weaknesses in bridges and other kinds of infrastructure.