纳米材料“ Elerographene”创建功能强大的泵

科学家开发了一种新方法，用于产生可控的电爆炸。从理论上讲，这只需要450克即可提起大象：“ Elerographene”欠其独特的结构。nano等级。视觉上类似于黑色泡沫，它实际上是由基于精致的管状网络组成的graphenewith numerous cavities. This makes it extremely stable, conductive and almost as lightweight as air.

The researchers have now taken a major step toward practical applications. They have succeeded in repeatedly heating and cooling aerograph and the air contained inside to very high temperatures in an extremely short period of time. This enables extremely powerful pumps, compressed air applications or sterilizing air filters in miniature.

“当我们第一次介绍这些materials，它们是迄今为止世界上最轻的材料，密度仅为每立方厘米0.2毫克。Rainer Adelung回忆说，因为这实际上是空气，我们称它们为“航空材料”。自那时以来，引起了全球兴趣，并经过深入研究，例如在欧洲主要的研究计划“石墨烯旗舰”中。

这项新研究为航空材料如何从基础研究到应用方面做出了贡献。来自基尔的物质科学家与来自丹麦南部丹麦大学，特伦托大学的伦敦皇后大学的丹麦大学的同事一起发现了进一步的财产，这些物业能够使气动技术创新，机器人技术或空气滤清器技术。

加热并快速冷却

"In our experiments, we have found that Aeromaterials made from graphene and other conductive nanomaterials, can be electrically heated extremely quickly with up to several hundred degrees per millisecond due to their low density," explains Dr. Fabian Schütt from CAU, who led and conducted the experiments together with Dr. Florian Rasch.

为此，材料科学家使用了“ Elerographene”航空材料，仅包括几层碳原子和99.9％的空气组成。加热时，材料内部的空气也会非常快速地加热并扩展。在非常迅速的供暖情况下，体积的扩张和一个说是“爆炸”。Schütt总结说：“这意味着我们现在能够使用Elerographene开始不需要化学反应的小型可控且可重复的爆炸。”

That's because almost as quickly as it heats up, aerographene cools down again as soon as the power supply is switched off. "It can hardly store any heat due to its extremely low heat capacity. Via its network structure it releases it very quickly back into the containing air," Schütt continues. The rapid heating and cooling of the material enables the researchers to start several explosions per second, one after the other. "This gives us extremely powerful compressed air at the push of a button, without the compressors and gas supplies that are otherwise required," Adelung explains.

Material withstood more than 100,000 cycles

The scientists use this effect to develop new pumps that can be specifically adjusted as well as high-performance actuators in miniature format. "If you place the aeromaterial in a pressure cylinder and heat it with electricity, the generated air blast can be used to move objects up and down in a targeted manner and several times per second," explains Rasch, who recently completed his doctoral thesis on this subject. In their experiments, the two first authors, Schütt and Rasch, were able to show that even a small amount of aerographene objects that are many times heavier can be moved. For example, 10 milligrams of aerographene were enough to lift a two-kilogram weight in just a few milliseconds. So the actuators developed with aerographene have high power densities while maintaining large volume changes.

Rasch说：“与化学反应相反，这些小型电爆炸可以非常具体地控制，也非常干净。通过改变当前供应的持续时间和强度，我们可以精确控制空气爆炸的频率和强度。”由于航空材料的极端电导率，它们仅需要少量电力。在基尔（Kiel）进行的实验中，该材料迄今已经受住了100,000个周期，并且已经提交了一项专利。

Self-cleaning air filter against bacteria

作为应用程序的一个例子,Adelung的研究h group is currently developing new air filter materials and systems based on aerographene in cooperation with the German aviation supplier Lufthansa Technik and funded by the Graphene Flagship. "Air currents can be guided very well through the open network structure of the material and can be heated strongly for a short time. In this way,bacteriaandviruses, for example, can be filtered out of the air and killed," Adelung said. "This could allow these filter systems to function self-cleaning and work without expensive maintenance in the future."

The article appeared as inMaterials Today.