您将学到什么：
- 如何将碳纳米管作为螺纹制造并组合以收获有用的功率。
- CNT所需的增强功能使它们通过Seebeck效应使其可行的热电能源来源。
- The results of the project, including fabric output power and efficiency power factor.
不乏研究效果，试图将织物用作能量收集的可行来源。这是有道理的，因为基于织物的收获似乎为这种剥削提供了肥沃的潜在领域。一种用于追求此目标的材料利用了碳纳米管（CNT），该碳纳米管（CNT）已经在该领域显示出许多独特而有用的特性。
A team based at Rice University, working in conjunction with Tokyo Metropolitan University, developed and transformed CNTs into a thermoelectric (TE) energy source in a fiber-enhanced, flexible-cotton fabric. It employs the well-known Seebeck effect to convert heat into enough energy to power an LED.
显然，使用碳纳米管有一些障碍。尽管如此，由于其一维性和独特的优势，例如灵活性和轻巧的重量，他们似乎是有希望的候选人。然而，保留宏观组装中个体碳纳米管的巨大功率因素是具有挑战性的，这主要是由于样品形态差和缺乏适当的费米能量调整。
费米能量（EF）是量子力学中的一个参数，它是指在绝对零温度下非相互作用费米的量子系统中最高和最低单粒子状态之间的能量差。该概念在描述和比较不同半导体的行为的高于0 K的温度以上是有用的。
高功率因子纤维
该团队生产的纤维和织物具有高价值的巨大功率因数（PF），这是由于他们通过出色的样品形态实现的超高电导率而产生的，并结合了通过费米能量调整增强的Seebeck系数。正如赖斯研究生和纸上纳西米·科马图（Natsumi Komatsu）的首席作者所指出的那样，“功率因数告诉您，在某些温度差和温度梯度的情况下，您可以从材料中获得多少功率密度。”（（笔记：这种收获功率因数与与交流电源和反应载荷相关的功率因数完全无关。）
他们坚持认为他们达到的PF -14（±5）mw/m-k2—is the highest value ever achieved for any CNT sample of macroscopic wearable fibers of aligned carbon nanotubes with ultra-high electrical and thermal conductivity（图。1）。
1. Textile thermoelectric (TE) generator based on carbon-nanotube (CNT) threads sewn into fabric: (a) Schematic and (b) photograph of the device. CNT threads (p-type thermoelectric generator) and steel threads (for electrical connection) were sewn into a fabric using a sewing machine. The CNT threads were connected electrically in series and thermally in parallel. A temperature difference ΔT was applied by heating one side (T热的）在保持对方的同时（tcold) at room temperature. (c) Electrical conductivity σ of one TEG unit as a function of bending radius, normalized by the conductivity without bending (σ0）。插图在测量过程中显示了设备的示意图和图片。（d）σ是弯曲数的函数，由原始状态的标准化（σ0）。The bending radius was 0.8 mm. The inset shows a schematic of the measurement procedure. (e) The entire device was connected to an LED through an amplification circuit and a capacitor. The LED turned on with a ΔT of ~50 K. (f) Output voltage and power as a function of applied ΔT. The inset shows a folded device, demonstrating its flexibility.
线缝制演示
CNT纤维可以通过使用商业缝纫机编织，甚至可以缝制，并且可以清洗 - 使用其他TE功能纤维很难实现。为了证明这一点，他们根据缝制在织物中的CNT螺纹制造了高性能的纺织TE发电机。该线是通过将21 cnt丝的平均螺纹直径为190μm产生的。他们将CNT螺纹和不锈钢线缝制成织物（100％棉），以使CNT螺纹串联连接，并平行地进行热连接（图2）。
2。Carbon nanotubes woven into thread-like fibers and sewn into fabrics become a thermoelectric generator that can turn heat from the sun or other sources into energy.
They then generated a temperature difference, ΔT, across the device by heating one side (T热的) with hotplates while keeping the other side (Tcold) at room temperature. The CNT threads generated power through the Seebeck effect, while the steel threads provided electrical connections（图3）。
3.（a）一个热电发生器（TEG）单元等于电压源和电阻器。b）LED电源的整个电路由四个连接的TEG单元组成，电容器，DC-DC转换器，LED和一个开关组成。当输入电压为40 mV或更高时，转换器将运行，并且根据输入电压和负载，输出电压在1到10 V之间。当开关连接到A时，电容器会被TEG填充；当它切换到B时，电容器会排放并点亮LED。
此外，他们观察到的巨大功率因子使这些纤维具有强大的候选热电学活性冷却领域的强大候选，这需要大型热电功率因数和同时具有较大的热导率。查看此简短的解释视频：
“Nanotubes have been around for 30 years, and scientifically, a lot is known,” added team member Junichiro Kono. “But in order to make real-world devices, we need macroscopically ordered or crystalline assemblies. Those are the types of nanotube samples that Matteo’s group and my group can make, and there are many, many possibilities for applications.”
他们如何生产CNT线程并调整费米能源的细节超出了讨论的范围，但是在他们的论文中提供了非常详细的信息。自然通讯“Macroscopic weavable fibers of carbon nanotubes with giant thermoelectric power factor。” In addition, the 36-pageSupplementary Informationfile provides extensive and in-depth information on the concept, implementation, deep-physics analysis, thermal analysis, test arrangements, results, and much more.
The research was supported by the Department of Energy Basic Energy Science program, the National Science Foundation, the Robert A. Welch Foundation, the Japan Society for the Promotion of Science, the U.S. Air Force, and the U.S. Department of Defense.
