Dynamics of Nanometer Gap Formation in Thermo-Tunneling Devices for Energy Conversion

热隧穿是一个术语，用来描述超热电子的综合发射(热离子发射)和电子通过两个表面之间的窄势垒的隧穿(场发射)。超热电子的热隧道效应在真空电子学和平板显示器等领域有着广泛的应用，在热电制冷和发电方面有着巨大的潜力。对热隧穿纳米结构的理论和实验研究表明，这些结构的散热效率可以接近卡诺效率的理论极限。该项目旨在通过在两个非常光滑的表面上形成一个非常窄(1纳米宽)的真空间隙来测试一种构建热隧道设备的新方法。不幸的是，在热隧穿器件实际使用所需的足够大的区域上建立纳米真空间隙是非常具有挑战性的，到目前为止还没有得到证实。因此，这项提议的目标是探索和证明利用洛伦茨、范德瓦尔斯和静电力之间的动态平衡在更大范围内创造纳米真空间隙的可行性。应用现代动力系统分析和分布参数系统边界控制的方法，从理论和实验上论证了形成这种间隙的可行性，并研制出一类新型的高效能量转换装置。如果成功，这项拟议的研究将产生一种新的纳米间隙形成技术，可用于固态冷却设备、固态热电发电机和国防(抗辐射)应用的高速真空电子设备。这种装置的能量转换效率接近热力学(卡诺)极限，因此，该项目可以通过在冷却应用中取代机械压缩机，或生产更高效的热电发电机，在冷却和发电应用中节省大量能源。这项研究将为亚利桑那大学应用数学跨学科项目的研究生提供宝贵的培训机会，并为他们与布达佩斯科技经济技术大学世界著名的应用力学系进行研究生交流提供宝贵的培训机会。

Thermo-tunneling is a term used to describe combined emission of hot electrons (thermionic emission) and tunneling of electrons through a narrow potential barrier between two surfaces (field emission). Thermo-tunneling of hot electrons across a few-nanometer gap has application to vacuum electronics and flat panel displays, and holds great potential in thermo-electric cooling and energy generation. Theoretical and experimental studies on thermo-tunneling nano-structures have shown that the heat removal efficiency of these structures could approach the theoretical limit known as Carnot efficiency. This project aims to test a new method for constructing thermo-tunneling devices by forming a very narrow (1 nanometer wide) vacuum gap across two very smooth surfaces. Unfortunately, establishment of a nanometer vacuum gap over sufficiently large areas required for practical use of thermo-tunneling devices is very challenging and so far has not been demonstrated. The goal of this proposal, therefore, is to explore and demonstrate the feasibility of creating nanometer vacuum gaps over extended areas using a dynamic equilibrium between Lorentz, Van der Waals, and electrostatic forces. The methods of modern dynamical system analysis and boundary control of distributed parameter systems will be applied to demonstrate theoretically and experimentally the feasibility of forming such gaps and to produce a new class of high-efficiency energy conversion devices. If successful, the proposed research will result in a novel nanometer gap-forming technique that can be used in solid-state cooling devices, solid-state thermoelectric generators, and high-speed vacuum electronic devices for defense (radiation hard) applications. The energy conversion efficiency of such devices approaches the thermodynamic (Carnot) limit, therefore the project could lead to tremendous energy savings in cooling and power-generation applications by replacing mechanical compressors in cooling applications, or producing a more efficient thermo-electric generators. The research will provide invaluable training opportunities for graduate students in the Applied Mathematics Interdisciplinary Program at the University of Arizona and for graduate student exchange with the world-renowned Department of Applied Mechanics at the Budapest Technical University of Technology and Economics.