A group of senior students from Zhejiang University have successfully developed an “air hand-washing device.” The device utilizes an infrared ray induction system， which detects the presence of hands. A tap then sprays a light water mist along with a strong gust of air， which the students have proven to be nearly as effective as traditional hand-washing. However， the device uses only 10 percent of the water that regular hand-washing does.

Li Qizhang， a member of the team that developed the device， told a reporter that a model of their device has already been installed in a classroom building at the university， and that the results have been satisfactory. The students have set up a company to further promote their product.

In 2014， a student named Chen Puyang first came up with the idea while washing his hands in the school cafeteria. Washing hands uses a lot of water， Chen thought. Would it be possible to replace the water with air？

Others may not have given the question a second thought. However， for Chen and Li， who were studying Fluid Mechanics， this constituted a brilliant idea。

Soon， Chen， Li and several classmates embarked on the project. The design of the device required knowledge from a variety of different majors， so the R&D team eventually came to be composed of seven students from various majors.

“We put different kinds of dirt on our hands and washed them with water. It turned out that 95 percent of water is used to flush away the dirt； only 5 percent is used to dissolve it. If we washed with only air， then the dirt on our hands would not dissolve. So we decided to use a fine water spray to complement the air. That way， the dirt is carried away by air and dissolved by water，” explained Li.

After a year of research and experimentation， the team came up with a gravity-driven hand-washing device whose reliance on water was minimal. The user stands on a platform in front of the device， which sinks because of the weight of the user. The gravity exerted by the user pulls the piston through a pulley block， and a gust of air is generated through air extrusion. The tap then releases a water mist coupled with the gust.

The team tested the device by conducting chromogenic reaction and residual bacteria experiments， which proved that the results of hand-washing with air can be similar to those of washing with water.

In September 2015， the team took its invention to the Global Grand Challenges Summit. They took home the top award， beating teams from 14 universities including MIT and Cambridge。

Now they have been developing a second generation of their product， which is powered by electricity and equipped with an infrared ray induction system.

浙江大學(xué)的一群大學(xué)生成功研制出“空氣洗手裝置”。該裝置利用紅外線感應(yīng)系統(tǒng)來探測(cè)雙手的位置。水龍頭隨之噴出霧狀水滴和高速氣流，學(xué)生們已經(jīng)證實(shí)了此方法和傳統(tǒng)的洗手方法一樣有效。然而，這種裝置僅僅消耗常規(guī)洗手方法10%的水量。

研發(fā)該裝置的團(tuán)隊(duì)成員之一李啟章告訴記者，他們?cè)诖髮W(xué)教學(xué)樓里已經(jīng)安裝了一臺(tái)，效果令人滿意。學(xué)生們還成立了一家公司進(jìn)一步推廣他們的產(chǎn)品。

2014年，陳濮陽在學(xué)校食堂洗手時(shí)突發(fā)奇想，用水洗手多浪費(fèi)啊，可以用空氣代替水洗手嗎？

旁人可能不會(huì)多想這個(gè)問題。但是，對(duì)于學(xué)習(xí)流體力學(xué)的陳濮陽和李啟章來說，這個(gè)問題構(gòu)思出一個(gè)好主意。

不久，陳、李和幾個(gè)同學(xué)開始著手這個(gè)計(jì)劃。裝置的設(shè)計(jì)需要各種專業(yè)知識(shí)，所以研發(fā)團(tuán)隊(duì)最終由7名來自不同專業(yè)的學(xué)生組成。

“通過用水來沖洗手上的各種污漬，我們發(fā)現(xiàn)95%的水都用于沖走污漬，只有5%的水用于溶解污漬。如果我們用空氣來沖洗手的話，手上的污漬則無法溶解，所以我們決定用水噴霧來彌補(bǔ)空氣的缺陷。用這個(gè)方法，污漬能被水溶解然后被空氣帶走?！崩顔⒄陆忉?。

經(jīng)過一年的研究實(shí)驗(yàn)，他們提出了重力驅(qū)動(dòng)洗手裝置，此裝置耗水量極少。當(dāng)使用者站在洗手裝置前的踏板上，踏板由于人體重力而下沉，通過滑輪組牽引活塞擠壓空氣獲得高速氣流，令水龍頭噴出水霧。

團(tuán)隊(duì)還通過顯色反應(yīng)和細(xì)菌殘留實(shí)驗(yàn)來測(cè)試裝置。實(shí)驗(yàn)證明空氣洗手的效果和傳統(tǒng)用水洗手的效果并無差異。

2015年9月，在全球重大挑戰(zhàn)峰會(huì)上，他們憑借這款發(fā)明，擊敗了包括麻省理工學(xué)院和劍橋大學(xué)在內(nèi)的14所大學(xué)，拿到了最高獎(jiǎng)項(xiàng)。

現(xiàn)在，他們正在研發(fā)電力驅(qū)動(dòng)配置紅外線感應(yīng)系統(tǒng)的新一代產(chǎn)品。