The Casimir Force in Complex Topologies and its Utility in Nanomachines

复杂拓扑中的卡西米尔力及其在纳米机器中的用途

• 批准号: EP/F035942/1
• 负责人: Chris Binns
• 金额: $ 37.92万
• 依托单位: University of Leicester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF035942%2F1
• 关键词: Casimir; Force; Complex; Topologies; its

Quantum theory predicts that a perfect vacuum from which all physical particles and all detectable energy have been removed is far from empty but contains a 'sea' of virtual particles that appear and disappear. These contribute to the so-called 'zero-point energy' of empty space (which is in fact collossal) on top of which all the physical processes that we are aware of take place. We have no way of detecting the zero-point energy directly since all the observable phenomena in our universe involve 'extra' energy on top of the vacuum level. The zero-point energy manifests itself in subtle ways however and one of them, predicted by Hendrik Casimir in 1948, is that two perfect reflectors placed in space disturb the local zero-point energy in such a way as to produce an attractive force between them. In the last decade the Casimir force has been measured quite accurately and comparisons with theory that include the actual reflectivity of real materials now agree with experiment to better than 10% and this strange 'force from nothing' is an experimental reality. The Casimir force becomes quite sginficant for gaps of less than 1micrometre and in micro-machines where gaps of this size and smaller are common it is quite a problem and generates a fundamental 'stickiness' in all components from which there is no escape. The Casimir force depends on the materials and topology of the cavity and learning to control it has become very important. In fact the latest research seeks to turn the problem on its head and use the Casimir force as a useful method to transmit force between neutral surfaces through vacuum without physical contact. In this respect a 'lateral' force reported between two corrugated surfaces is particularly useful since moving one surface tends to drag the other remote surface in the same direction. There are now predictions of even more interesting effects, for example it is possible to obtain a continuous lateral force in one direction on a symmetrical rack by oscillating a similar rack in a direction parallel to the two racks. It is predicted that it will also be possible to control the direction of the force by varying the rack topology, separation and oscilation frequency. It should also be possible to obtain a continuous lateral linear force on an asymmetric rack pair (Casimir ratchet) by oscillating the racks in a direction perpendicular to each and again control the magnitude and direction of the force. The consortium in this proposal consists of experimental and theory groups working directly in this field and a micro-machine capable of measuring the lateral Casimir force in these different geometries has been designed.The most radical idea in this proposal is to attempt to reverse the sign of the Casimir force to produce repulsion between the surfaces by coating one of the surfaces with a 'metamaterial'. These are films with an artificially produced nanostructure, for example arrays of tiny metal rings, whose optical properties can be controlled. Using the electron beam lithography facilities available in the consortium we estimate that we will be able to produce a metamaterial that generates repulsion at a separation between the plates where it is easily measurable. Such a repulsive force will revolutionise the design of micro/nano-machines and will enable the creeation of totally frictionless bearing surfaces. The research done in this project will produce a 'toolkit' of controllable forces, all obtained purely from vacuum, which can be utilised in new designs of micro/nano-machines. We will demonstrate the utility of the repulsive force by designing a new type of micro-accelerometer based on it.

量子理论预言，一个完美的真空，所有的物理粒子和所有可探测的能量都被移除，远不是空的，而是包含一个出现和消失的虚拟粒子的“海洋”。这些有助于空的空间（实际上是collosal）的所谓“零点能量”，我们所知道的所有物理过程都发生在这个空间之上。我们没有办法直接检测零点能量，因为我们宇宙中所有可观察到的现象都涉及真空能级之上的“额外”能量。零点能以微妙的方式表现出来，其中之一，亨德里克·卡西米尔在1948年预测，是两个完美的反射器放置在空间中，以这种方式干扰局部零点能，从而在它们之间产生吸引力。在过去的十年中，卡西米尔力已经被相当准确地测量，并且与包括真实的材料的实际反射率在内的理论进行比较，现在与实验的一致性超过10%，这种奇怪的“无中生有的力”是实验现实。卡西米尔力对于小于1微米的间隙变得非常重要，并且在这种尺寸和更小的间隙常见的微型机器中，卡西米尔力是一个相当大的问题，并且在所有组件中产生基本的“粘性”，无法逃脱。Casimir力取决于腔的材料和拓扑结构，学会控制它变得非常重要。事实上，最新的研究试图把这个问题放在它的头上，并使用卡西米尔力作为一种有用的方法，通过真空在中性表面之间传递力，而无需物理接触。在这方面，在两个波纹表面之间报告的“横向”力是特别有用的，因为移动一个表面往往会在同一方向上拖动另一个远程表面。现在有预测甚至更有趣的效果，例如，它是可能的，以获得一个连续的横向力在一个方向上的对称机架上的摆动类似的齿条在一个方向上平行于两个齿条。据预测，它也将有可能通过改变机架拓扑结构，分离和振荡频率来控制力的方向。还应该可以通过使齿条在垂直于每个齿条的方向上振荡来在非对称齿条对（Casimir棘轮）上获得连续的横向线性力，并且再次控制力的大小和方向。在这个提案中的财团由实验和理论小组直接在这一领域的工作和微型机器能够测量横向Casimir力在这些不同的几何形状已经designed.The最激进的想法在这个提案是试图扭转的Casimir力的符号之间产生排斥的表面涂层的表面与'超材料'。这些薄膜具有人工制造的纳米结构，例如微小金属环阵列，其光学特性可以控制。利用该联盟提供的电子束光刻设备，我们估计我们将能够生产出一种超材料，该材料在板之间的分离处产生排斥力，在那里它很容易测量。这种排斥力将彻底改变微/纳米机器的设计，并将使完全无摩擦的轴承表面的创造成为可能。在这个项目中完成的研究将产生一个可控力的“工具包”，所有这些力都是完全从真空中获得的，可以用于微/纳米机器的新设计。我们将通过设计一种基于该斥力的新型微加速度计来证明斥力的实用性。

项目成果

Measurement of the Casimir effect under ultrahigh vacuum: Calibration method

超高真空下卡西米尔效应的测量：校准方法

• DOI: 10.1116/1.3322734
• 发表时间: 2010
• 期刊: Materials, Processing, Measurement, and Phenomena
• 作者: Torricelli G

Casimir Force Contrast Between Amorphous and Crystalline Phases of AIST

• DOI: 10.1002/adfm.201200641
• 发表时间: 2012-09
• 期刊: Advanced Functional Materials
• 影响因子: 19
• 作者: G. Torricelli;P. J. van Zwol;O. Shpak;G. Palasantzas;V. Svetovoy;C. Binns;B. Kooi;P. Jost;M. Wuttig

Switching Casimir forces with Phase Change Materials

用相变材料切换卡西米尔力

• DOI: 10.48550/arxiv.1006.4065
• 发表时间: 2010
• 作者: Torricelli G