{"id":165777,"date":"2025-07-31T14:01:02","date_gmt":"2025-07-31T18:01:02","guid":{"rendered":"https:\/\/www.bu.edu\/eng\/?p=165777"},"modified":"2025-07-31T14:01:02","modified_gmt":"2025-07-31T18:01:02","slug":"this-smarter-sound-shield-blocks-more-noise-without-blocking-air","status":"publish","type":"post","link":"https:\/\/www.bu.edu\/eng\/2025\/07\/31\/this-smarter-sound-shield-blocks-more-noise-without-blocking-air\/","title":{"rendered":"This Smarter Sound Shield Blocks More Noise\u2014Without Blocking Air"},"content":{"rendered":"

Building on their 2019 breakthrough, researchers unveil a new ultra-open metamaterial that silences a broader range of noise while preserving ventilation.<\/strong><\/h3>\n

A new breakthrough from the Zhang Lab at Boston University is making waves in the world of sound control. Led by\u00a0<\/span>Professor Xin Zhang<\/span><\/a>\u00a0(ME<\/a>, ECE<\/a>, BME<\/a>, MSE<\/a>), the team has published a new paper in\u00a0<\/span>Scientific Reports<\/span><\/i>\u00a0titled \u201c<\/span>Phase gradient ultra open metamaterials for broadband acoustic silencing<\/span><\/i><\/a>.\u201d The article marks a major advance in their long-running Acoustic Metamaterial Silencer project.<\/span><\/p>\n

The\u00a0<\/span>Zhang lab<\/span><\/a>\u00a0is renowned in the fields of metamaterials and microsystems for its continual advancement of real-world applications. Back in 2019, their research on an Acoustic Metamaterial Silencer\u2014or \u201csound shield\u201d\u2014aimed to \u201csignificantly block sound while maintaining airflow, based on Fano resonance effects,\u201d in the lab\u2019s words. At the time,\u00a0 applications focused on fans, propellers, and HVAC systems, targeting the reduction of narrowband noise while preserving air passage (<\/span>see the 2019\u00a0<\/span>Brink<\/span><\/i>\u00a0article for more<\/span><\/a>\u00a0on the original breakthrough).<\/span><\/p>\n

\"Xin
Xin Zhang (ME, ECE, BME, MSE)<\/em><\/figcaption><\/figure>\n

Since then, the Zhang lab has extended its work to explore a broader range of acoustic silencing strategies\u2014including multi-band, broadband, and tunable approaches\u2014making the technology viable in new environments such as factories, offices, and public spaces, where diverse and unpredictable sound frequencies are common and airflow remains essential.<\/span><\/p>\n

Their latest advance centers on broadband silencing. While this broader control came with a modest trade-off in peak silencing performance\u2014a common challenge when shifting from narrowband to broadband suppression\u2014it unlocked powerful new possibilities. The breakthrough was made possible through the use of phase-gradient metamaterials, giving rise to the Phase Gradient Ultra-Open Metamaterial (PGUOM).<\/span><\/p>\n

\u201cPGUOM takes a smarter approach\u2014more like noise-canceling headphones\u2014effectively silencing a broadband of unwanted sounds,” says Zhang. “It remains highly effective even as the noise shifts in pitch or volume, making it far more practical in dynamic settings like open offices, ventilation systems, or transportation hubs, where sound sources are unpredictable and span a wide range of frequencies.\u201d<\/span><\/p>\n

Read the full story on the BU Photonics Center website<\/a>.<\/strong><\/em><\/h3>\n","protected":false},"excerpt":{"rendered":"

The breakthrough was made possible through the use of phase-gradient metamaterials.<\/p>\n","protected":false},"author":2662,"featured_media":165784,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[236,257,899,907,909,908,1052],"tags":[708],"_links":{"self":[{"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/posts\/165777"}],"collection":[{"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/users\/2662"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/comments?post=165777"}],"version-history":[{"count":3,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/posts\/165777\/revisions"}],"predecessor-version":[{"id":165786,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/posts\/165777\/revisions\/165786"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/media\/165784"}],"wp:attachment":[{"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/media?parent=165777"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/categories?post=165777"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bu.edu\/eng\/wp-json\/wp\/v2\/tags?post=165777"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}