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科学家研制出廉价石墨烯海绵传感器 新传感器摒弃了阻止传感器应用和发展的诸多限制。最近几年，在操作纳米结构并用其制造性能卓越的探测器以精确追踪空气中的化学物质方面，科学家们已经取得了重大的进步，然而，他们研制出的各式各样的传感器，尽管从理论上而言很好，但却并不实用。 目前传感器的设计都非常复杂，常常依赖单个纳米结构，而且，科学家们需要对这样的结构进行仔细操作以及更加精确的分析。另外，制造出的传感器往往不能重复使用，且必须在特定的温度或压力下才能工作，因此，科学家们一直没有制造出一款可靠、便宜且可以重复使用的手持传感设备。 现在，伦斯勒理工学院的科学家们使用石墨烯泡沫研制出了这种邮票大小的新型传感器。他们将石墨烯，即单层碳原子，种植在泡沫镍结构上，随后移除泡沫镍，留下一个类似泡沫的石墨烯结构，其具有独特的电性，能够用于执行传感任务。 当将其暴露于空气中时，空气中的粒子会被吸收到泡沫表面，而且每个这样的粒子会用不同的方式影响石墨烯泡沫，对其电阻进行微小的改动。让电流通过其中并且测量电阻的变化，就能知道泡沫上依附的是什么粒子。科学家们让大约100毫安的电流通过该泡沫，结果发现，这种石墨烯泡沫能够导致粒子解吸，也就是说，粒子自动从传感器上剥落下来，清除这些粒子，传感器就可以重复使用了。 科学家们对传感器进行了微调，让其来探测氨水（自制爆 炸物硝酸氨的关键成分），该石墨烯泡沫传感器在5分钟到10分钟内就设法探测到了这种富有攻击性的粒子，而且效率是现有市面上最好探测器的10倍。科学家们接着用其来探测有毒 气体二氧化氮（爆 炸物分解的时候也会释放出这种气体），结果表明，其效率也是目前商用传感器的10倍。 石墨烯泡沫非常容易处理且操作简单，而且在室温下也能很好地工作，这都是科学家们非常心仪的特质，该石墨烯泡沫传感器可让科学家们更快制造出更便宜实用的手持传感设备来对大气进行探测。 分享到：
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最新评论
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titanlizard 2011-11-29 19:44来学习了啊
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ascs5566 2011-11-29 20:51学习！搞起~~
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quanliwei 2011-11-29 21:23很霸道
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kerwin 2011-11-29 21:25学习下……谢谢了
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GGJ312 2011-11-29 21:59路过看看
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mang2004 2011-11-30 00:11加强学习。多谢分享。
上原文过过瘾。
Using Graphene Foam to Detect Gases RPI
Nanotechnology as a discipline is bleeding-edge cool, but so often we hear more about its amazing potential than its practical application. So it’s always refreshing to catch wind of a story like this: Researchers at Rensselaer Polytechnic Institute in New York have developed and demonstrated a small, relatively inexpensive, and reusable sensor made of graphene foam that far outperforms commercial gas sensors on the market today and could lead to better explosives detectors and environmental sensors in the very near future.
The new sensor dispenses with a lot of the limitations that have been holding back sensors in this space. In the last several years, many strides have been made in the science of manipulating nanostructures to be excellent detectors of very fine trace elements of chemicals on the air. But these sensors, while great in theory, are impractical in actual service.
Current sensor designs are complex, often relying on an individual nanostructure that must be carefully manipulated and even more carefully analyzed. They are often not reusable and must be deployed at specific temperatures or pressures, making a handheld sensor device unreliable, very expensive, and impossible to use repeatedly.
Enter graphene foam. The new postage-stamp-sized sensor developed at RPI involves growing graphene--one-atom-thick layers of carbon--on a structure of nickel foam. Removing that nickel foam leaves behind a structure of foam-like graphene with unique electrical properties that can be tuned to the task of sensing.
When exposed to air, particles adsorb to the foam’s surface. And each of these particles affects the graphene foam in a different way, slightly modifying its electrical resistance. Run a current through it, and a measurement of the change in resistance tells a you what’s sticking to the foam. Moreover, by running a roughy 100-milliampere current through the foam the RPI team found they could cause the particles to desorb--that is, they unattached themselves from the sensor, cleansing it so it can be used again and again.
Tweaked to detect ammonia (a key ingredient in homemade explosive ammonium nitrate--think: fertilizer bombs), the graphene foam sensor managed to detect the offending particle at just 1,000 parts-per-million in just five-to-10 minutes--making it ten times more effective than the best detectors on the market today. A second demo involving nitrogen dioxide (another trace element given off by explosives as they degrade) showed nearly identical results--effective at 100 parts-per-million, or ten times better than current commercial sensors.
Given that graphene foam is fairly easy to handle and manipulate given its larger size and room-temperature-ready performance, that’s pretty remarkable. It also drastically lowers the barrier to a practical handheld devices for atmospheric sensing.
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知日月 2011-12-05 10:55石墨烯泡沫。。。很抽象。。。
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10000高伟 2011-12-06 22:31传感器很重要，且极其具有发展前景！