【作者】 焦焱；

【导师】 刘林华； Pei-feng Hsu；

【作者基本信息】 哈尔滨工业大学 ， 工程热物理， 2013， 博士

【摘要】 随着工业技术的发展，电子、机械、航天、生物、医药学等各领域的设备器件均从传统工艺向微型工艺发展，微电子机械系统(MEMS)成为一个新兴的技术领域。系统结构的微小型化使得工业界面临机遇与挑战并存的境地。一方面，微小型化产生了系统散热困难，热光电系统转化效率低等问题；另一方面，微结构内具有的一些特殊辐射特性为上述问题的解决提供了新的方案和思路。目前，已有诸多研究工作针对利用微结构的辐射特性，满足工业应用需求，解决技术难题。但由于微结构辐射特性研究仍处于起步阶段，很多设计难以满足工业要求。基于上述研究背景，为深入发展微尺度结构表面辐射特性调控技术，利用其特点解决工业技术难题，提高应用系统性能，本文针对以辐射为主要能量传递和转换方式的应用领域，如热光电转换系统、航天器热控制系统等，对周期性微结构表面的辐射特性进行了研究，提出了选择性吸收峰等效带宽的拓宽技术和三种主动调控光谱特性的周期性微结构。使用严格耦合波分析法，结合等效LC回路模型理论，对提出的微结构表面辐射特性和辐射机理进行了研究，有效改善了系统辐射性能，进一步满足了工业应用的实际需要，为实际应用提供了理论基础。其中主要工作包括：鉴于周期性光栅结构表面光谱辐射特性具有不同的机制，本文分别研究了光栅辐射特性随入射波类型、入射角度、光栅结构尺度和材料的变化规律。结果表明，磁极化比等离子激元极化更适宜作为调节辐射特性的共振机制。该机制形成的共振峰位置、峰值大小和半波全宽均可按规律通过光栅几何结构尺寸进行调节。材料的吸收性能与其消光系数和折射率的比值κ/n成反比。金属铝、金和银因其在中远红外波段恒定的吸收率及较强的导电性而较适合选作微结构表面的加工材料。实际应用中常遇到简单光栅结构的高吸收率共振峰过窄，不能满足航天器热控系统的宽谱带波长选择性散热需求的问题。本文进行了等效吸收带宽的拓宽方法研究，提出了二重凹槽光栅和复杂二重凹槽光栅两种等效吸收带宽拓宽结构。该方法通过结构设计实现不同波段共振峰的毗连，从而达到在宽波段范围激发高吸收率峰的目的。研究结果通过等效带宽增益系数的比较，证实该两种结构可以有效提高指定波段的等效吸收带宽。实现根据应用环境变化主动调节表面的光谱辐射特性有助于在实际应用中提高辐射散热设备的机动能力。本文提出了移动盖板光栅结构、填充液光栅结构和梳齿微驱动器光栅结构三种光谱辐射特性主动调控方法，并对其共振激发机制和调控规律进行了研究。研究表明，此三种结构可分别通过改变盖板厚度和位置，调节填充液材料和高度，以及调整梳齿几何尺寸和位置对光栅光谱辐射特性进行有效调节。从而实现了微结构加工成型后的辐射特性调控功能，加强了微结构表面光谱辐射特性调控能力的灵活性和在不同应用环境下的兼容性。更多还原

【Abstract】 As the development of technology, the equipments in differnet fields, such aselectronics, mechanism, aerospace, biology, medicine, turn to minitype fromtraditional technics. Micro-electromechanical systems (MEMS) become an risingtechnolgoy field. The minimization of system structures brings the industry fileds toa position that facing to both opportunities and challenges. On the one hand, severaldifficulties, such as harder to dissipate heat, lower transform efficiency ofthermophotovaltic system, are produced. On the other hand, the special properties ofmicro-scale structures provide some new methods and ideas to solve those problems.Recently, there have been some researches about meeting the industrial applicationrequirments by the radiation properties of micro-structures. However, since theresearches about micro-structure radiation are not mature, there are still lots ofrequirements in practical application can not be satisfied.Based on the above background, in order to develop the radiation propertycontrol technology of microscale structure surface to solve industrial problems andimprove the application system performance, this paper does some researches aboutthe spectral radiation properties of periodic micro-scale structure surface. Theresearch of this paper aims to the application field that take radiation as the mainenergy transition and transfer way, such as thermophotovoltaic system andaerospace thermal control system. In this study, two methods are proposed to widenthe equivalent absorptance wavelength band. And it also proposes three newstructures for active control of radiaiton properties. The spectral properties andresonance mechanism are studied by rigourous coupled-wave analysis combinedwith the equivalent LC circuit model theory. It is found that the radiation propertiesof systems are much improved and meet the requirment of practicle applicationsbetter. The scope of present study contains three parts:There are several different adjust mechanisms for the radiation properties ofperiodic grating structure surface. The changing law of grating radiation propertieswith incident ray, grating structure demensions and grating materials areinvestigated in this paper. The results show that the absorptance peaks excited byMagnetic Polaritons (MPs) are properer for radiaiton adjustment than that excited bySurface Plasmon/Phonon Polaritons (SPPs). The absorptance peaks excited by MPscan be adjusted by changing the grating structure dimensions. The absorbency ofmaterials is inversely proportional to (κ/n)2. Aluminum, gold and silver are proper tothe materials of periodic micro-structure due to their strong electrical conductivityand constant absorptance in mid-and far-infrared wave band. The high absorptance peaks excited by simple grating are too narrow to meetthe requirement of aerospace thermal control system. This paper proposes adual-groove grating structure and a complex dual-groove grating structure forpassive control of system radiation property. It is proved that these two structuresincreased the effecitve wave band within interested wavelength band by combiningabsorptance peaks excited in different wavelength through structrue design. And thesimulation shows that these two structures are promising for specral radiaitonproperty improvement.It is helpful to improve the flexbility and manoeuvrability of radiation heatdisspation equipments. A sliding cover board grating structure, a filling solutiongrating structure and a comb-driven micro-actuator grating structure are proposedfor active control of system spectal radiaiton properties. The resonance mechanismand adjusting laws are investigated. It is proved that the absorptance peaks can beadjusted by changing the thickness and position of cover board, height of fillingsolutions and geometry dimensions or displacement of comb finger. This designprovides the posibility of adjusting system radiation property after the graitngstructures are frabricated, thus enable change the spectral properties according toenvironment demand.更多还原