For those of you that resented math at school, Boston University engineers have shown how it can be applied for useful, fun and practical applications.
By using mathematics and 3D printing, the engineers developed an acoustic metamaterial which is open in shape, maintains airflow and still sends incoming sounds back to where they came from.
The results of the researchers’ work can be found on APS Physic’s Physical Review B. In it, the team detail previous, successful acoustic metamaterials, but with only a small proportion of their area allowing the passage of air.
Bringing the instant, iterative production power of 3D printing to bear, along with mathematically perfect specifications, the researchers yielded a 3D printed noise barrier that not only blocks 94% of all sound passing through but is 60% open for the passage of air.
Testing the 3D Printed Acoustic Metamaterial
To test the 3D print, the researchers sealed a loudspeaker to one end of a large polyvinyl chloride (PVC) pipe. To the other end of the opening, they secured the 3D printed acoustic metamaterial.
When they pressed play, the loudspeaker began blasting a high-pitched sound but those on the other side of the acoustic metamaterial couldn’t hear a thing.
The acoustic metamaterial could be likened to a mute button, with the engineers finding that it silenced nearly all sound from the loudspeaker.
“The moment we first placed and removed the silencer…was literally night and day,” said Jacob Nikolajczyk, study co-author. “We had been seeing these sorts of results in our computer modeling for months — but it is one thing to see modeled sound pressure levels on a computer, and another to hear its impact yourself.”
The engineers intend on using their work to silence irritating noises out in the real world. Xin Zhang, a professor at Boston University, adds: “Drones are a very hot topic. Companies like Amazon are interested in using drones to deliver goods, she says, and “people are complaining about the potential noise.”
Source: Tech2
License: The text of "Boston Engineers 3D Print Open Noise-Cancelling Metamaterials" by All3DP is licensed under a Creative Commons Attribution 4.0 International License.