王中林在展示新型纳米管今天看到一篇英文报导,介绍摩擦生电在未来也许可以给手机充电,感觉是很新颖的概念,这里就转载一下。联想到前几天写的《科学家实现豚鼠内耳供电:人体电池或成真》,我感慨颇多,随着科技的发展,许多看似不可能的事情也许在不久的将来就真的能够出现在我们眼前了。移动电源在现在来说是非常必须的物品,但是几年以后可能会有更适合的替代品诞生。

How Friction May Someday Charge Your Cell Phone

The phenomenon that causes a painful shock when you touch metal after dragging your shoes on the carpet could someday be harnessed to charge personal electronics.

摩擦生电是众所周知的物理现象,那么有没有想过利用摩擦产生的电能给手机充电?一种由廉价材料制造的纳米发电机或许将实现这一功能。

Researchers at Georgia Tech have created a device that takes advantage of static electricity to convert movement—like a phone bouncing around in your pocket—into enough power to charge a cell phone battery. It is the first demonstration that these kinds of materials have enough oomph to power personal electronics.

佐治亚理工学院的研究人员已经开发出一款原型产品,能利用运动,例如手机在口袋中的晃动,产生的静电给手机电池充电。这是业界首次实现利用这样的电能给个人电子设备充电。

Excess energy produced when you walk, fidget, or even breathe can, in theory, be scavenged to power medical implants and other electronics. However, taking advantage of the energy in these small motions is challenging.

从理论上讲,人们行走,甚至呼吸产生的能量都可以给植入体内的医疗设备,或其他电子产品充电。然而,如何利用这种小幅运动产生的能量则存在挑战。

Zhong Lin Wang, a professor of materials science at Georgia Tech, has been working on the problem for several years, mostly focusing on piezoelectric materials that generate an electrical voltage under mechanical stress (see “Harnessing Hamster Power with a Nanogenerator”). Wang and others have amplified the piezoelectric effect by making materials structured at the nanoscale. So far, though, piezoelectric nanogenerators have not had very impressive power output.

佐治亚理工材料科学专业教授王中林在过去多年中一直从事这一领域的研究,并主要专注于压电材料。通过采用纳米技术来制造压电材料,王中林和同事放大了压电效应。不过到目前为止,基于压电效应的纳米发电机还没有产生较大的电力输出。

Now Wang’s group has demonstrated that a different approach may be more promising: static electricity and friction. This is the effect at work when you run a plastic comb through your hair on a dry day, and it stands on end. The Georgia Tech researchers demonstrated that this static charge phenomenon, called the triboelectric effect, can be harnessed to produce power using a type of plastic, polyethylene terephthalate, and a metal. When thin films of these materials come into contact with one another, they become charged. And when the two films are flexed, a current flows between them, which can be harnessed to charge a battery. When the two surfaces are patterned with nanoscale structures, their surface area is much greater, and so is the friction between the materials—and the power they can produce.

王中林的小组发现,一种不同的方式可能更有前景:静电和摩擦。在干燥的天气使用塑料梳子梳头就很容易产生静电。研究人员证明,使用一片聚对苯二甲酸乙二醇酯材料和一片金属材料,这种静电充电现象,或称作“摩擦起电”效应,能产生足够的能量。当弯曲时,两片薄膜之间将产生电流,从而实现充电。而如果采用纳米技术来制造两种表面,那么有效面积将更大,从而提供更强的摩擦和更多的电能。

The Georgia Tech nanogenerator can convert 10 to 15 percent of the energy in mechanical motions into electricity, and thinner materials should be able to convert as much as 40 percent, Wang says. A fingernail-sized square of the triboelectric nanomaterial can produce eight milliwatts when flexed, enough power to run a pacemaker. A patch that’s five by five centimeters can light up 600 LEDs at once, or charge a lithium-ion battery that can then power a commercial cell phone. Wang’s group described these results online in the journal Nano Letters.

佐治亚理工学院发明的这种纳米发电机能将机械运动能量的10%至15%转换为电能,而更薄的材料转换率甚至可以达到40%。指甲盖大小的摩擦电纳米材料在弯曲时能产生8毫瓦电力,足以驱动心脏起搏器。而一块5×5厘米的材料能同时点亮600盏LED灯泡,或是为商用手机的电池充电。王中林的小组已经在《Nano Letters》期刊上发表了研究成果。

“The choice of materials is wide, and fabricating the device is easy,” says Wang. Any of about 50 common plastics, metals, and other materials can be paired to make this type of device.

王中林表示:“材料的选择很多,设备的制造也很容易。”有约50种普通塑料、金属和其他材料在配对时都可以产生同样的效果。

“I’m impressed with the power density here,” says Shashank Priya, director of the Center for Energy Harvesting Materials and Systems at Virginia Tech. Other smart materials haven’t produced enough power for practical applications, he says.

弗吉尼亚理工学院能源利用材料与系统中心主管Shashank Priya表示:“这一设备产生的能量密度很高。”他指出,其他智能材料还无法产生可实际应用的足够能量。

Whether the new nanogenerator will work outside the lab remains to be seen. “They need to demonstrate that this can generate power from mechanical vibrations in real life,” says Jiangyu Li, professor of mechanical engineering at the University of Washington in Seattle. To work in the real world, an energy scavenger will have to be able to pick up on vibrational frequencies that provide the most energy. A nanogenerator that can only pick up on low-energy mechanical vibrations would take way too long to charge a cell phone, Priya notes. Wang says he is in talks with companies about developing the energy scavenger for particular applications, and envisions it being worn on an armband.

目前还不清楚这样的纳米发电机是否能在实验室之外得到应用。华盛顿大学机械工程专业教授Li Jiangyu表示:“他们还需要证明,现实生活中的机械震动能产生能量。”为了在现实中应用,纳米发电机需要利用提供能量最多的震动频率,而如果纳米发电机只能利用低能量机械震动,那么为手机充电花费的时间将太长。王中林表示,他正在与一些企业讨论,开发应用在特定场合的纳米发电机。

虽然这些技术非常实用,可是真正要普及还需要一个过程,作为普通消费者的我们恐怕一时半会用不上,真想用摩擦生电给手机充电也许还得等上好几年吧,所以选择一款优秀的品牌移动电源还是很有必要的,如果近期有购买打算,推荐看看我的置顶文章《[精品推荐]移动电源哪个牌子好》。