Latest Science News -- ScienceDaily
Breaking science news and articles on global warming, extrasolar planets, stem cells, bird flu, autism, nanotechnology, dinosaurs, evolution -- the latest discoveries in astronomy, anthropology, biology, chemistry, climate and environment, computers, engineering, health and medicine, math, physics, psychology, technology, and more -- from the world's leading universities and research organizations.
Nanoscale pillars could radically improve conversion of heat to electricity
Feb 20th 2014, 21:13
University of Colorado Boulder scientists have found a creative way to radically improve thermoelectric materials, a finding that could one day lead to the development of improved solar panels, more energy-efficient cooling equipment, and even the creation of new devices that could turn the vast amounts of heat wasted at power plants into more electricity.
The technique -- building an array of tiny pillars on top of a sheet of thermoelectric material -- represents an entirely new way of attacking a century-old problem, said Mahmoud Hussein, an assistant professor of aerospace engineering sciences who pioneered the discovery.
The thermoelectric effect, first discovered in the 1800s, refers to the ability to generate an electric current from a temperature difference between one side of a material and the other. Conversely, applying an electric voltage to a thermoelectric material can cause one side of the material to heat up while the other stays cool, or, alternatively, one side to cool down while the other stays hot.
Devices that incorporate thermoelectric materials have been used in both ways: to create electricity from a heat source, such as the sun, for example, or to cool precision instruments by consuming electricity.
However, the widespread use of thermoelectric materials has been hindered by a fundamental problem that has kept scientists busy for decades. Materials that allow electricity to flow through them also allow heat to flow through them. This means that at the same time a temperature difference creates an electric potential, the temperature difference itself begins to dissipate, weakening the current it created.
Until the 1990s, scientists addressed this problem by looking for materials with intrinsic properties that allowed electricity to flow more easily than heat.
"Until 20 years ago, people were looking at the chemistry of the materials," Hussein said. "And then nanotechnology came into the picture and allowed researchers to engineer the materials for the properties they wanted."
Using nanotechnology, material physicists began creating barriers in thermoelectric materials -- such as holes or particles -- that impeded the flow of heat more than the flow of electricity. But even under the best scenario, the flow of electrons -- which carry electric energy -- also was slowed.
In a new study published in the journal Physical Review Letters, Hussein and doctoral student Bruce Davis demonstrate that nanotechnology could be used in an entirely different way to slow the heat transfer without affecting the motion of electrons.
The new concept involves building an array of nanoscale pillars on top of a sheet of a thermoelectric material, such as silicon, to form what the authors call a "nanophononic metamaterial." Heat is carried through the material as a series of vibrations, known as phonons. The atoms making up the miniature pillars also vibrate at a variety of frequencies. Davis and Hussein used a computer model to show that the vibrations of the pillars would interact with the vibrations of the phonons, slowing down the flow of heat. The pillar vibrations are not expected to affect the electric current.
The team estimates that their nanoscale pillars could reduce the heat flow through a material by half, but the reduction could be significantly stronger because the calculations were made very conservatively, Hussein said.
"If we can improve thermoelectric energy conversion significantly, there will be all kinds of important practical applications," Hussein said. These include recapturing the waste heat emitted by different types of equipment -- from laptops to cars to power plants -- and turning that heat into electricity. Better thermoelectrics also could vastly improve the efficiency of solar panels and refrigeration devices.
The next step is for Hussein to partner with colleagues in the physics department and other institutions to fabricate the pillars so that the idea can be tested in the lab. "This is still early in the phase of laboratory demonstration but the remaining steps are within reach."
Hussein also hopes to further refine the models he used to gain additional insight into the underlying physics. "A team of highly motivated Ph.D. students are working with me around the clock on this project," he said.
The research was funded by the National Science Foundation.
This entry passed through the Full-Text RSS service — if this is your content and you're reading it on someone else's site, please read the FAQ at fivefilters.org/content-only/faq.php#publishers.
You are receiving this email because you subscribed to this feed at https://blogtrottr.com
If you no longer wish to receive these emails, you can unsubscribe here:
- Solidot: 政治倾向由生理决定，而非理智
- Solidot: 魁北克省要求店主将Facebook页面内容翻译成法语
- Solidot: 科学出版商移除一百多篇机器生成的假论文
- Solidot: 英国政府提出新规定允许“三亲胚胎”
- Solidot: 波音Black手机的更多细节公开
- Solidot: MtGox申请破产保护
- Solidot: Debian移植到OpenRISC架构
- Solidot: 2014年Gnome亚洲峰会定在北京举行
- Solidot: 用LED路灯提供移动服务
- Solidot: 印度空间研究组织公布载人太空船原型
- Solidot: 华纳兄弟将制作《Minecraft》电影
- Solidot: Tor正在开发匿名即时聊天工具
- Solidot: ArnoldC：出自施瓦辛格电影的编程语言
- Solidot: 明报前总编被砍引发新闻自由的担忧
- Solidot: MtGox关闭后火币网交易量暴增
- Solidot: GCHQ拦截雅虎用户的视频聊天，发现许多人裸聊
- Solidot: 中国成立网络安全最高委员会
- Solidot: 中国科学家认为短距离水下量子通信是可能的
- Solidot: 美国儿童正在变瘦
- Solidot: 美国一参议员呼吁封杀比特币
- Solidot: Opera迎来丰收的一年
- Solidot: Chris Anderson的开源无人机王国
- Solidot: 中国科学家成功去除猴子的特定基因
- Confirm your unsubscription from '网易数码频道：相机资讯'
- Solidot: GitHub公开文本编辑器Atom
- Solidot: 上海禁止早晚高峰使用打车软件
- Solidot: P2P僵尸网络
- Solidot: 波音为政府研发具有自毁功能的Android手机
- Solidot: 两款Ubuntu手机原型亮相MWC
- Solidot: 亚马逊的甜言蜜语
- Solidot: 确认的太阳系外行星数量增至1700颗
- Solidot: 三星Tizen OS：没有Android应用的Android克隆
- Solidot: Google被勒令移除反穆斯林视频
- Solidot: 用基于WebGL的BabylonJS把3D扫描模型分享给小伙伴
- Solidot: GreatFire.org合作新闻网站被屏蔽
- Solidot: 依靠IDE让你变成一位差劲的程序员？
- Solidot: 骆家辉：中国未来美好，需要尊重法治和保障人权
- Solidot: 暴雪证实计划向玩家出售60美元的90级角色升级商品
- Solidot: 中国智能电网投入超过美国
- Solidot: Android木马利用Tor隐藏指令服务器位置
- Solidot: Wolfram演示Wolfram语言
- Solidot: 传记作者曝光Julian Assange的秘密生活
- Solidot: 诺基亚XL：大屏大抱负
- Solidot: Servo：Mozilla试图重新发明浏览器
- Solidot: 朝鲜叛逃者用气球反击平壤
- Solidot: 防监听手机Blackphone的更多细节
- Solidot: Twitter用户剧透《壮志凌云》，派拉蒙发出DMCA通知
- Solidot: MtGox收到美国传票，日本着手调查
- Solidot: 评估报告称国际热核聚变实验堆存在严重管理问题
- Solidot: Portal 2 Beta for Linux版发布
- Solidot: 苹果督促亚利桑那州州长否决反同性恋法案
- Solidot: 世卫组织警告北京空气污染，气象局呼吁民众hold住
- Solidot: 福特车载信息系统用QNX替代Windows
- Solidot: 科学家用鱼线创造人造肌肉
- Solidot: 安全研究员开发出能绕过微软EMET的攻击代码
- Solidot: 新西兰因计算机系统问题向错误的司机开出2万罚单法
- Solidot: 新浪微博用户增长速度创下新低
- Solidot: Pony僵尸网络从感染者机器上窃走了价值22万美元的数字货币
- Solidot: 巴西和欧洲宣布铺设绕过美国的海底光缆
- Solidot: 三星发布Galaxy S5——防水版Galaxy S4
- Solidot: MtGox关闭交易，关闭网站
- Solidot: 用大数据监控分析员工行为
- Solidot: PLoS要求论文作者公开数据
- Solidot: 市场因素迫使污染大户钢厂倒闭
- Solidot: 中国扩增新闻道德委员会
- Solidot: LinkedIn发布中文版，取名领英
- Solidot: Google将发布新版Google地图
- Solidot: 月球遭遇有记录以来最明亮的小行星撞击
- Confirm your unsubscription from 'Latest Science N...
- Solidot: 报告称95%的野鸡大学文凭授予了中国人
- Solidot: 哈佛超算集群被劫持挖掘狗币
- Solidot: 数字电影能保存100年吗？
- Latest Science News -- ScienceDaily: Synthetic ver...
- Latest Science News -- ScienceDaily: United Kingdo...
- Latest Science News -- ScienceDaily: New insights ...
- Solidot: 成人电影工作室用数字技术移除安全套
- Solidot: 神经学研究发现，程序语言确实像外语
- Solidot: 诺基亚公布三款Android手机
- Solidot: 腾讯金山等宣布向XP提供技术支持
- Confirm your unsubscription from '网易数码频道：家电资讯'
- Solidot: 微软证实Windows 8.1下一次更新将以非触摸设备为重心
- Solidot: 地球上最古老的岩石在澳大利亚
- Solidot: 香港首家比特币零售店周五开放
- Solidot: WhatsApp创始人用不可改签的机票向Facebook施压
- Solidot: NSA不再监听总理而去监听德国部长
- Solidot: 为什么专利和版权在中国难以实施？
- Solidot: gotofail：苹果 SSL/TLS 重大安全漏洞的细节
- Solidot: NASA公布宇航员拍摄的朝鲜夜晚照片
- Solidot: 中国律师要求公安部公布监控信息
- Solidot: Mozilla计划向新兴市场发布25美元智能手机
- Solidot: 高频交易员开始使用激光通信
- Solidot: 三星的智能手表运行Tizen
- Solidot: Stack Overflow公布用户调查结果
- Solidot: Chrome 33新变化引发用户强烈抗议
- Solidot: Bruce Schneier建议解散NSA
- Latest Science News -- ScienceDaily: Seed-filled b...
- Latest Science News -- ScienceDaily: Revolutionary...
- Latest Science News -- ScienceDaily: Is a 'buttery...
- Confirm your unsubscription from '网易科技频道IT业界新闻'
- Solidot: 数学模型预测革命
- ▼ 二月 (840)
- ► 2013 (16909)