as reported by ETH News<\/a>) and helmets all the way to microelectronics.<\/p>\nSpecial properties thanks to a special microstructure <\/p>\n
Dennis Kochmann, Professor of Mechanics and Materials Research at ETH Zurich has extensively worked on metamaterials in his research. \u201cIt is fascinating how, through a special microstructure, you can endow a material with special properties that it does not possess without this structure,\u201d he explains.<\/p>\n
Kochmann and his collaborators recently presented a novel so-called phononic metamaterial in two scientific publications \u2013 a material capable of precisely controlling mechanical waves, such as vibrations or acoustic signals.<\/p>\n
Such a metamaterial could, for example, be deployed to harvest energy from vibrations or to process signals purely mechanically, which is of interest for sensors and mechanical computers that operate without electricity.<\/p>\n
Wafer-thin silicon membrane as a wave guide <\/p>\n
If a metal plate is excited to vibrate \u2013 for example, by hitting it with a hammer \u2013 these vibrations usually spread in a circular fashion, similar to surface waves in water. If this plate has a carefully designed structure, however, it can redirect waves along specific paths \u2013 and it is precisely this effect that the ETH researchers have exploited.<\/p>\n
Instead of a metal plate, they used an extremely thin silicon membrane into which the researchers etched countless holes by way of photolithography and etching techniques, thereby forming a specific pattern.<\/p>\n
A pattern comprising millions of elements <\/p>\n
The pattern consists of millions of repeating square elements \u2013 minute squares, each further divided diagonally into four squares. At the centre of the main square is a four-pointed star.<\/p>\n
Unlike in many other metamaterials, these unit cells are not identical across the entire pattern but change incrementally, as the lengths of the star\u2019s arms vary.<\/p>\n
The ETH researchers used custom-built computer models to generate these patterns and simulated how a wave striking the pattern propagates in rays.<\/p>\n
\u201cIf one were to simulate the entire wave field in a conventional manner, it would be extremely computationally expensive, because the design space is huge with millions upon millions of degrees of freedom,\u201d explains Kochmann\u2019s former team member Charles Dorn, now an assistant professor at the University of Washington, who was in charge of the simulations.<\/p>\n
Playing puzzle with metamaterials <\/p>\n
\u201cThe design of our metamaterial is modular, just like a jigsaw puzzle,\u201d as Kochmann explains. In this way, different puzzle pieces perform specific functions, such as deflecting rays at right angles or splitting waves into different directions based on their frequency. When the researchers skilfully assemble the appropriate puzzle pieces, they can generate complex wave paths, such as a figure-eight path.<\/p>\n","protected":false},"excerpt":{"rendered":"Metamaterials \u2013 the term may sound esoteric to the layman. In science and engineering, however, this is an…\n","protected":false},"author":2,"featured_media":75331,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[6],"tags":[5977,6397,1202,51],"class_list":["post-75330","post","type-post","status-publish","format-standard","has-post-thumbnail","category-zurich","tag-d-mavt","tag-engineering-sciences","tag-news","tag-zurich"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@ch\/116672303196737015","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/posts\/75330","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/comments?post=75330"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/posts\/75330\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/media\/75331"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/media?parent=75330"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/categories?post=75330"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ch\/wp-json\/wp\/v2\/tags?post=75330"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}