Empa researchers developed chiral phononic crystals and built a functional model on which vibration measurements are now carried out. Image: Empa
A team of Empa acoustic researchers has built macroscopic crystal structures that use internal rotation to attenuate the propagation of waves. The method makes it possible to build very light and stiff materials that can also "swallow" low frequencies very well, as they report Communicatons. The world of crystals offers many interesting properties: crystals can strike electric sparks in disposable lighters, for example, they can produce polarized light and they can scatter bundled X-rays into thousands of individual reflexes that are refracted in all spatial directions. Some of these properties are retained even if the atomic crystal structures are enlarged about 100,000,000 times and the crystals are replicated on a large scale. Physicists have been taking advantage of this for several years now: If the original crystals scatter X-rays with very short wavelengths, the enlarged copies can scatter oscillations with long wavelengths in all directions. A very elegant way for vibration damping has thus been found. Enlarged crystal structures with such acoustic properties are called phononic crystals.
TO READ THIS ARTICLE, CREATE YOUR ACCOUNT
And extend your reading, free of charge and with no commitment.
