Posted on 01/01/2019 8:12:58 PM PST by BenLurkin
According to a new paper published today in Nature Materials, the newly engineered material creates a robust acoustic structure that can control in unusual ways the propagation and localization of sound even when fabrication imperfections exist. This unique property may improve technologies that use sound waves, such as sonars and ultrasound devices, making them more resistant to defects.
Using topological principles, researchers predicted and later discovered topological insulators—special materials that conduct electric currents only on their edges, not in the bulk. Their unusual conduction properties stem from the topology of their electronic band gap, and they are therefore unusually resistant to continuous changes, such as disorder, noise or imperfections.
…
To design their novel acoustic metamaterial, the team 3-D-printed a series of small trimers, arranged and connected in a triangular lattice. Each trimer unit consisted of three acoustic resonators. The rotational symmetry of the trimers, and the generalized chiral symmetry of the lattice, gave the structure unique acoustic properties that stem from the topology of their acoustic bandgap.
The acoustic modes of the resonators hybridized, giving rise to an acoustic band structure for the whole object. As a result, when sound is played at frequencies outside the band gap it can propagate through the bulk of the material. But when sound is played at frequencies inside the band gap, it can only travel along the triangle's edges or be localized at its corners. This property, Alù says, is not affected by disorder or fabrication errors.
"You could completely remove a corner, and whatever is left will form the lattice's new corner, and it will still work in a similar way, because of the robustness of these properties," Alù said
(Excerpt) Read more at phys.org ...
If the Gap Band played music through the band gap, would anyone hear it ?
Would this thing work to filter out rap music ?
“The rotational symmetry of the trimers, and the generalized chiral symmetry of the lattice, gave the structure unique acoustic properties that stem from the topology of their acoustic bandgap.”
That’s what I’ve been saying all along.
LOL! That sentence threw me over the edge too.
That water is way too deep for me.
Suddenly I feel like I’m in Professor Irwin Corey’s class.
Unobtanium!
Vibranium discovered!
I can almost hear it now.... “TURN THAT G’DAMN THING DOWN!!!”
Lol.
I didn’t even think twice about that sentence; I read similar sentences every day.
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