{"id":74538,"date":"2025-06-30T16:24:02","date_gmt":"2025-06-30T14:24:02","guid":{"rendered":"https:\/\/www.iemn.fr\/?p=74538"},"modified":"2025-07-02T08:16:47","modified_gmt":"2025-07-02T06:16:47","slug":"when-ultrasound-makes-optical-surfaces-self-cleaningansforms-optics-into-self-cleaning-surfaces","status":"publish","type":"post","link":"https:\/\/www.iemn.fr\/en\/newsletter\/when-ultrasound-makes-optical-surfaces-self-cleaningansforms-optics-into-self-cleaning-surfaces.html","title":{"rendered":"Cleardrop: When Ultrasound Makes Optical Surfaces Self-Cleaning"},"content":{"rendered":"<div  class='flex_column av-37avgsy-0d9504ce59532ccd4a7dbbe9019ea900 av_one_full  avia-builder-el-0  el_before_av_one_full  avia-builder-el-first  first flex_column_div'     ><section  class='av_textblock_section av-mcj3sznm-aae2c58783ee23e882349930f6048864'   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p><a href=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/cleardrop.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-74515 aligncenter\" src=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/cleardrop.jpg\" alt=\"\" width=\"350\" height=\"133\" srcset=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/cleardrop.jpg 350w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/cleardrop-300x114.jpg 300w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/cleardrop-18x7.jpg 18w\" sizes=\"auto, (max-width: 350px) 100vw, 350px\" \/><\/a><\/p>\n<\/div><\/section><\/div>\n<div  class='flex_column av-2jpe6vm-26161ff44249b0a3503a5636ce04d089 av_one_full  avia-builder-el-2  el_after_av_one_full  el_before_av_one_fourth  first flex_column_div  column-top-margin'     ><style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-mcj3uy6t-e91687e046c85a1eeaa9ec27d3b00c20\">\n#top .av-special-heading.av-mcj3uy6t-e91687e046c85a1eeaa9ec27d3b00c20{\npadding-bottom:10px;\ncolor:#3966c6;\n}\nbody .av-special-heading.av-mcj3uy6t-e91687e046c85a1eeaa9ec27d3b00c20 .av-special-heading-tag .heading-char{\nfont-size:25px;\n}\n.av-special-heading.av-mcj3uy6t-e91687e046c85a1eeaa9ec27d3b00c20 .special-heading-inner-border{\nborder-color:#3966c6;\n}\n.av-special-heading.av-mcj3uy6t-e91687e046c85a1eeaa9ec27d3b00c20 .av-subheading{\nfont-size:15px;\n}\n<\/style>\n<div  class='av-special-heading av-mcj3uy6t-e91687e046c85a1eeaa9ec27d3b00c20 av-special-heading-h2 custom-color-heading  avia-builder-el-3  avia-builder-el-no-sibling'><h2 class='av-special-heading-tag'  itemprop=\"headline\"  >Cleardrop: When Ultrasound Makes Optical Surfaces Self-Cleaning<\/h2><div class=\"special-heading-border\"><div class=\"special-heading-inner-border\"><\/div><\/div><\/div><\/div>\n<div  class='flex_column av-w84ppu-828ed77ce224812119062ab5b38fe2ee av_one_fourth  avia-builder-el-4  el_after_av_one_full  el_before_av_three_fifth  first flex_column_div  column-top-margin'     ><\/div>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-1xnrdhu-a45fcf3c6fd884ad53247dcf6d5d3f7a\">\n.flex_column.av-1xnrdhu-a45fcf3c6fd884ad53247dcf6d5d3f7a{\nborder-radius:15px 15px 15px 15px;\npadding:0 0 0 0;\n}\n<\/style>\n<div  class='flex_column av-1xnrdhu-a45fcf3c6fd884ad53247dcf6d5d3f7a av_three_fifth  avia-builder-el-5  el_after_av_one_fourth  el_before_av_one_half  flex_column_div av-zero-column-padding  column-top-margin'     ><style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-1qd2xea-618116798e9668e28d25419607c43464\">\n#top .av_textblock_section.av-1qd2xea-618116798e9668e28d25419607c43464 .avia_textblock{\nfont-size:15px;\ncolor:#177ce8;\ntext-align:justify;\n}\n<\/style>\n<section  class='av_textblock_section av-1qd2xea-618116798e9668e28d25419607c43464'   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock custom-quote invalid-custom-class-found position relative font-style italic padding em em margin em invalid-custom-class-found background-color f9f9f9 border-left px solid ccc font-size em color invalid-custom-class-found invalid-custom-class-found custom-quotebefore invalid-custom-class-found content invalid-custom-class-found font-size em position absolute top px left px color ccc line-height invalid-custom-class-found font-family Georgia serif invalid-custom-class-found av_inherit_color'  itemprop=\"text\" ><p><strong><span style=\"color: #999999;\">\u00ab\u00a0Maintaining perfect visibility regardless of weather conditions is essential for many applications ranging from surveillance cameras to autonomous systems such as drones and solar panels, which can lose up to 50% of their efficiency when not cleaned regularly. To address this challenge, VISION, a spin-off from the IEMN, has developed an integrated optical surface cleaning technology based on <b>ultrasonic surface waves<\/b>\"\u00a0<\/span><\/strong><\/p>\n<\/div><\/section><\/div>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-1pd6hma-8ac581f9eedb750f9a880212e5e1c1b7\">\n@keyframes av_boxShadowEffect_av-1pd6hma-8ac581f9eedb750f9a880212e5e1c1b7-column {\n0%   { box-shadow:  0 0 0 0 #d3d3d3; opacity: 1; }\n100% { box-shadow:  0 0 10px 0 #d3d3d3; opacity: 1; }\n}\n.flex_column.av-1pd6hma-8ac581f9eedb750f9a880212e5e1c1b7{\nbox-shadow: 0 0 10px 0 #d3d3d3;\nborder-width:2px;\nborder-color:#eaeaea;\nborder-style:solid;\nborder-radius:15px 15px 15px 15px;\npadding:15px 15px 15px 15px;\n}\n<\/style>\n<div  class='flex_column av-1pd6hma-8ac581f9eedb750f9a880212e5e1c1b7 av_one_half  avia-builder-el-7  el_after_av_three_fifth  el_before_av_one_half  first flex_column_div shadow-not-animated'     ><style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-mcj4lrwd-6dcaf8623e0b93537aff7473b4effbdb\">\n#top .av_textblock_section.av-mcj4lrwd-6dcaf8623e0b93537aff7473b4effbdb .avia_textblock{\ntext-align:justify;\n}\n<\/style>\n<section  class='av_textblock_section av-mcj4lrwd-6dcaf8623e0b93537aff7473b4effbdb'   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p>Cleardrop technology, developed and patented as part of a partnership between the start-up VISION and researchers at the IEMN, is based on the use of surface acoustic waves to clean all types of contamination (droplets, solid particles, snow, frost, mud) from optical surfaces.<\/p>\n<p>Physically, \u2018nano-earthquakes\u2019 are generated by piezoelectric actuators on the surface of a substrate. These vibrations, known as Rayleigh waves, have a very low amplitude (in the picometre or nanometre range) and a very high frequency (several million vibrations per second), making them invisible to the naked eye. Their energy remains localised on the surface, allowing very efficient transmission to any liquid or solid inclusions present.<\/p>\n<p>In the case of liquid inclusions, the waves propagate inside the droplet at an angle determined by Snell&rsquo;s law. This radiation generates (i) an internal flow called \u2018streaming\u2019 and (ii) a force known as \u2018acoustic radiation force\u2019, which together contribute to asymmetrically deforming the droplet and inducing its displacement in the direction of wave propagation. In the case of solid particles, these are accelerated by the elliptical deformation of the surface, causing the particles to jump in the opposite direction to the wave propagation. The solid particles therefore move in the opposite direction to the propagation of the waves.<\/p>\n<p>Thanks to these mechanisms, it is possible to clean any type of inclusion present on an optical surface in less than a second. Cleardrop&rsquo;s work has consisted of making this technology, initially developed in the laboratory on piezoelectric substrates, functional on all types of optical surfaces.<\/p>\n<hr \/>\n<p>More informations :<\/p>\n<p><a href=\"https:\/\/clearsolar.tech\/\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-74553 alignleft\" src=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/solar.jpg\" alt=\"\" width=\"200\" height=\"62\" srcset=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/solar.jpg 449w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/solar-300x94.jpg 300w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/solar-18x6.jpg 18w\" sizes=\"auto, (max-width: 200px) 100vw, 200px\" \/><\/a><\/p>\n<p><a href=\"https:\/\/cleardrop.tech\/\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-74551\" src=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/cleardrop-1.jpg\" alt=\"\" width=\"202\" height=\"77\" srcset=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/cleardrop-1.jpg 350w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/cleardrop-1-300x114.jpg 300w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/cleardrop-1-18x7.jpg 18w\" sizes=\"auto, (max-width: 202px) 100vw, 202px\" \/><\/a><\/p>\n<p style=\"text-align: left;\"><span style=\"text-decoration: underline;\">Contact Us<\/span> : <a href=\"mailto:michael.baudoin@univ-lille.fr\" target=\"_blank\" rel=\"noopener\">michael.baudoin@univ-lille.fr<\/a><\/p>\n<\/div><\/section><\/div>\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-11bv302-6d7541f368c51f1b62ae3082675709b4\">\n@keyframes av_boxShadowEffect_av-11bv302-6d7541f368c51f1b62ae3082675709b4-column {\n0%   { box-shadow:  0 0 0 0 #d6d6d6; opacity: 1; }\n100% { box-shadow:  0 0 10px 0 #d6d6d6; opacity: 1; }\n}\n.flex_column.av-11bv302-6d7541f368c51f1b62ae3082675709b4{\nbox-shadow: 0 0 10px 0 #d6d6d6;\nborder-radius:15px 15px 15px 15px;\npadding:15px 15px 15px 15px;\n}\n<\/style>\n<div  class='flex_column av-11bv302-6d7541f368c51f1b62ae3082675709b4 av_one_half  avia-builder-el-9  el_after_av_one_half  el_before_av_hr  flex_column_div shadow-not-animated'     ><section  class='av_textblock_section av-23li5u-ed136d8240baffe481b0e2bd16958955'   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p><a href=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/CleardropV2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-74523 aligncenter\" src=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/CleardropV2.jpg\" alt=\"\" width=\"439\" height=\"426\" srcset=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/CleardropV2.jpg 439w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/CleardropV2-300x291.jpg 300w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/CleardropV2-12x12.jpg 12w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2025\/06\/CleardropV2-36x36.jpg 36w\" sizes=\"auto, (max-width: 439px) 100vw, 439px\" \/><\/a><\/p>\n<\/div><\/section><\/div><\/p>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-18maygi-4342869e34285f08f49eb7e3c3aebac7\">\n#top .hr.av-18maygi-4342869e34285f08f49eb7e3c3aebac7{\nmargin-top:30px;\nmargin-bottom:30px;\n}\n.hr.av-18maygi-4342869e34285f08f49eb7e3c3aebac7 .hr-inner{\nwidth:350px;\nborder-color:#358be8;\nmax-width:45%;\n}\n<\/style>\n<div  class='hr av-18maygi-4342869e34285f08f49eb7e3c3aebac7 hr-custom  avia-builder-el-11  el_after_av_one_half  el_before_av_one_full  hr-center hr-icon-yes'><span class='hr-inner inner-border-av-border-fat'><span class=\"hr-inner-style\"><\/span><\/span><span class='av-seperator-icon' aria-hidden='true' data-av_icon='\ue823' data-av_iconfont='entypo-fontello'><\/span><span class='hr-inner inner-border-av-border-fat'><span class=\"hr-inner-style\"><\/span><\/span><\/div>\n<div  class='flex_column av-j1k3f6-99ef2a7d1b2f0ed3db384ae1e6fc2278 av_one_full  avia-builder-el-12  el_after_av_hr  avia-builder-el-last  first flex_column_div'     ><section  class='av_textblock_section av-mcj5kw9x-9b157cb2c2fa8e91b7474c4c51e5ee9e'   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p><u>References for physics<\/u>:<\/p>\n<p style=\"text-align: left;\">[1] N. Chastrette, M. Baudoin, P. Brunet, L. Royon, R. Wunenburger, Elucidating the oscillation instability of sessile drops triggered by surface acoustic waves, Phys. Rev. Fluids, 7: 124201 (2022)<br \/>\n[2] A. Bussoni\u00e8re, M. Baudoin, P. Brunet and O. Bou Matar, Dynamics of sessile and pendant drop excited by surface acoustic waves: gravity effects and correlation between oscillatory and translational motions, Phys. Rev. E, 93: 053106 (2016)<br \/>\n[3] M. Baudoin, P. Brunet, O. Bou-Matar, E. Herth, Low power sessile droplet actuation via modulated surface acoustic waves, Appl. Phys. Lett., 100: 154102 (2012)<br \/>\n[5] P. Brunet, M. Baudoin, O. Bou Matar, F. Zoueshtiagh, Droplet displacement and oscillations induced by ultrasonic surface acoustic waves: a quantitative study, Phys. Rev. E, 81: 026315 (2010)<\/p>\n<\/div><\/section><\/div>","protected":false},"excerpt":{"rendered":"","protected":false},"author":20,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[297],"tags":[],"class_list":["post-74538","post","type-post","status-publish","format-standard","hentry","category-newsletter"],"_links":{"self":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/74538","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/users\/20"}],"replies":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/comments?post=74538"}],"version-history":[{"count":11,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/74538\/revisions"}],"predecessor-version":[{"id":74640,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/74538\/revisions\/74640"}],"wp:attachment":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/media?parent=74538"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/categories?post=74538"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/tags?post=74538"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}