appearing today in the journal Nature Communications<\/a>. The study\u2019s first author is Ikra Iftekhar Shuvo, an MIT graduate student in media arts and sciences, along with Carlos D\u00edaz-Mar\u00edn, Marvin Christen, Michael Lherbette, and Christopher Liem.<\/p>\nPrecious hours<\/p>\n
Boriskina\u2019s group at MIT develops materials that interact with the environment in novel ways. Recently, her group explored atmospheric water harvesting (AWH), and ways that materials can be designed to efficiently absorb water from the air. The hope is that, if they can work reliably, AWH systems would be of most benefit to communities where traditional sources of drinking water \u2014 and even saltwater \u2014 are scarce.<\/p>\n
Like other groups, Boriskina\u2019s lab had generally assumed that an AWH system in the field would absorb moisture during the night, and then use the heat from the sun during the day to naturally evaporate the water and condense it for collection.<\/p>\n
\u201cAny material that\u2019s very good at capturing water doesn\u2019t want to part with that water,\u201d Boriskina explains. \u201cSo you need to put a lot of energy and precious hours into pulling water out of the material.\u201d<\/p>\n
She realized there could be a faster way to recover water after Ikra Shuvo joined her group. Shuvo had been working with ultrasound for wearable medical device applications. When he and Boriskina considered ideas for new projects, they realized that ultrasound could be a way to speed up the recovery step in atmospheric water harvesting.<\/p>\n
\u201cIt clicked: We have this big problem we\u2019re trying to solve, and now Ikra seemed to have a tool that can be used to solve this problem,\u201d Boriskina recalls.<\/p>\n
Water dance<\/p>\n
Ultrasound, or ultrasonic waves, are acoustic pressure waves that travel at frequencies of over 20 kilohertz (20,000 cycles per second). Such high-frequency waves are not visible or audible to humans. And, as the team found, ultrasound vibrates at just the right frequency to shake water out of a material.<\/p>\n
\u201cWith ultrasound, we can precisely break the weak bonds between water molecules and the sites where they\u2019re sitting,\u201d Shuvo says. \u201cIt\u2019s like the water is dancing with the waves, and this targeted disturbance creates momentum that releases the water molecules, and we can see them shake out in droplets.\u201d<\/p>\n
Shuvo and Boriskina designed a new ultrasonic actuator to recover water from an atmospheric water harvesting material. The heart of the device is a flat ceramic ring that vibrates when voltage is applied. This ring is surrounded by an outer ring that is studded with tiny nozzles. Water droplets that shake out of a material can drop through the nozzle and into collection vessels attached above and below the vibrating ring.<\/p>\n
They tested the device on a previously designed atmospheric water harvesting material. Using quarter-sized samples of the material, the team first placed each sample in a humidity chamber, set to various humidity levels. Over time, the samples absorbed moisture and became saturated. The researchers then placed each sample on the ultrasonic actuator and powered it on to vibrate at ultrasonic frequencies. In all cases, the device was able to shake out enough water to dry out each sample in just a few minutes.<\/p>\n
The researchers calculate that, compared to using heat from the sun, the ultrasonic design is 45 times more efficient at extracting water from the same material.<\/p>\n
\u201cThe beauty of this device is that it\u2019s completely complementary and can be an add-on to almost any sorbent material,\u201d says Boriskina, who envisions a practical, household system might consist of a fast-absorbing material and an ultrasonic actuator, each about the size of a window. Once the material is saturated, the actuator would briefly turn on, powered by a solar cell, to shake out the water. The material would then be ready to harvest more water, in multiple cycles throughout a single day.<\/p>\n
\u201cIt\u2019s all about how much water you can extract per day,\u201d she says. \u201cWith ultrasound, we can recover water quickly, and cycle again and again. That can add up to a lot per day.\u201d<\/p>\n
This work was supported, in part, by the MIT Abdul Latif Jameel Water and Food Systems Lab and the MIT-Israel Zuckerman STEM Fund.<\/p>\n
This work was carried out in part by using MIT.nano and ISN facilities at MIT.<\/p>\n","protected":false},"excerpt":{"rendered":"Feeling thirsty? Why not tap into the air? Even in desert conditions, there exists some level of humidity…\n","protected":false},"author":2,"featured_media":302864,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[32],"tags":[157445,157444,157448,157449,157447,58723,79,157443,157446],"class_list":["post-302863","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-atmospheric-water-harvesting","tag-ikra-iftekhar-shuvo","tag-mit-mechanical-engineering-research","tag-mit-media-lab-research","tag-moisture-extraction","tag-safe-drinking-water","tag-science","tag-svetlana-boriskina","tag-ultrasonic-devices"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/302863","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=302863"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/302863\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/302864"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=302863"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=302863"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=302863"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}