Our ears sometimes can’t stand the noises produced by factory machines, big vehicles, heavy construction equipment and even jet engines. Above all, if these noises are used for one good purpose then we won’t mind at all even if the noises are loud enough to pierce through our ears. But, don’t worry, this method can dampen the noise, too.
After long years of research, engineers have finally figured out how to generate and harvest energy from sound. They believe this neat physics trick could soon muffle the high pitched uproar in the factories and jet engines; and also generate wind power.
During the experiment, separate team of investigators developed prototype devices where they were made to pass through the noisy hatchway just to initiate the sensors inside.
Stephen Horowitz, a research engineer at Ducommun Miltec says these sensors can dampen the sound of the noise itself and he has been began looking at this noise problem a decade ago while he was a student at the University of Florida.
“We were looking at engine liners and noise reduction technologies to quiet engines,” Horowitz said. “We began looking at the fact that there is a lot of acoustic energy in that environment.”
While he and his colleagues were working on the jet engines, they realized the roar of jet engine revs (Rate of revolution of a motor) more than 130 decibel (enough to induce pain), could be changed into electrical energy. This is when he started working on piezoelectric effect with his graduate adviser professor Mark Sheplak.
Piezoelectricity is the electricity developed in certain crystals by mechanical strain and these materials can convert mechanical signals (such as sound waves) into electrical signals, and vice versa. Also, these materials can take the stress and strain of mechanical motions.
Using this material, they built an extremely sensitive and thin membrane out of aluminium that could transform the vibration made by sound into electricity, just enough to power a small sensor. This membrane is then attached to a special liner that cancels certain frequencies which will tone down the noise.
Horowitz says the advantage of a sound-powered sensor is that you don’t have to use batteries or wires to run the engine sensor, making it easier to maintain.
The project is being funded by NASA and they are helping aircraft makers come up with quieter jet engines.