Interactions between micro-plasma devices

等离子体--物质的第四种状态--是一种呈现集体现象的电离气体。等离子体在我们日常生活中的突出作用在很大程度上仍然是隐藏的；许多产品如果没有等离子体就不能存在。它们是电视显示器、移动电话、太阳能电池、纳米芯片制造、航空航天应用、高效照明、生物医学、癌症治疗等技术的基础。因此，等离子体通常被称为未来的纳米级工程工具。吸引人的基础科学问题和应用所产生的巨大社会影响推动了等离子体科学与技术领域的发展。低温等离子体的独特之处在于等离子体物种不处于热力学平衡状态。这些等离子体由电子、离子和中性粒子组成。电子温度在10000-50000 K左右，而较重的离子和中性粒子在室温附近。热电子可以在冷气体中提供独特的活跃的化学环境。这为表面的精确处理和改性提供了设备--即使是半导体或生物材料等温度敏感的表面。特别具有挑战性的是在常压下运行的所谓微等离子体的新兴领域，同时也非常有希望。微等离子体被限制在微米尺度上，目前可能是低温等离子体科学中最热门的话题。人们可以设想开发廉价的一次性微型等离子体源。可以在低气体温度下提供高浓度的自由基，而无需复杂的真空设备，例如在常压条件下用于杀菌和癌症治疗。这些领域是具有巨大未来产业效益和社会意义的前沿技术。该项目是关于多个微等离子体相互作用机制的基础研究，为将这一研究领域提升到一个新的水平提供了难得的机会。理解基本过程的一个关键问题是深入了解功率耦合和等离子体维持机制，从而智能地使用它们来定制等离子体属性。最近在理解单个微等离子体设备方面取得了一些进展，但多个微等离子体设备之间的相互作用要复杂得多。在多个器件中，例如微等离子体阵列，单个器件相互作用，并且它们的耦合可以导致图案和结构的形成。对相关相互作用机制的详细研究是缺乏的，但对于微等离子体阵列的进一步发展和开发至关重要。理解这种相互作用的关键是研究能量传输机制的细节。重要的因素是载能粒子(电子、离子、自由基、亚稳态)、辐射传输和光电离以及与材料有关的表面反应的个体作用。微等离子体的测量具有极大的挑战性，因为它们的结构非常小(微米级)，而且以碰撞为主的高压环境要求极高的时间分辨率，精度可达皮秒。基本诊断是最新可用的现代光学诊断技术和激光光谱学--两者都具有皮秒分辨率。最有希望的方法是利用这些超高速诊断技术和最先进的数字计算机模拟的协同作用。

Plasma - the 4th state of matter - is an ionized gas exhibiting collective phenomena. The outstanding role of plasmas in our daily lives remains largely hidden; many products could not exist without plasmas. They underlie technologies, such as TV-displays, mobile phones, solar-cells, nano-chip fabrication, aerospace applications, high-efficiency lighting, biomedicine, cancer treatment, etc. Plasmas are, therefore, often referred to as nano-scale engineering tools of the future.Both fascinating fundamental scientific issues and the enormous social impact that result from their applications drive the field of plasma science and technology. The unique property of low temperature plasmas lies in the fact that the plasma species are not in thermodynamic equilibrium. These plasmas consist of electrons, ions and neutrals. Electron temperatures are around 10000 - 50000 K, while the heavier ions and neutrals are around room temperature. The 'hot' electrons can provide a unique active chemical environment in a cold gas. This offers the facility for precise treatment and modifications of surfaces - even temperature sensitive surfaces such as semiconductors or bio-materials.Particularly challenging and at the same time highly promising is the emerging field of so-called micro-plasmas operated at ambient atmospheric pressure. Micro-plasmas are confined to dimensions on a micro-metre scale and are at present probably the 'hottest' topic in low-temperature plasma science. One can envisage the development of inexpensive disposable micro-plasma sources. High concentrations of radicals can be provided at low gas temperatures without complicated vacuum equipment, e.g. for sterilization and cancer treatments under atmospheric pressure conditions. These areas are frontier technologies with enormous future industrial benefit and social significance.The proposed project, on fundamental investigations of interaction mechanisms between multiple micro-plasmas, provides extraordinary opportunity to lift this research area to its next level. A key issue in understanding fundamental processes, towards their intelligent use for tailoring plasma properties, is insight into power coupling and plasma sustainment mechanisms. There has been some recent progress in understanding single micro-plasma devices, but the interaction of multiple micro-plasma devices is far more complex. In multiple devices, e.g. micro-plasma arrays, single devices interact with each other and their coupling can result in pattern and structure formation. Detailed studies of relevant interaction mechanisms are absent but crucial for further developments and exploitations of micro-plasma arrays. The key to understanding the interaction is to investigate details of energy transport mechanisms. Important factors are the individual roles of energy carrying particles (electrons, ions, radicals, metastables), radiation transport and photo-ionization, and material dependent surface reactions.Measurements on micro-plasmas are extremely challenging due to their very small structures (micron scale) and the collision dominated high-pressure environment requiring exceptionally high temporal resolution down to pico-seconds. Essential diagnostics are newly available modern optical diagnostic techniques and laser spectroscopy - both with pico-second resolution. The most promising approach is exploiting the synergy of these ultrafast diagnostic techniques and state-of-the-art numerical computer simulations.