Fundamental spectroscopic diagnostics of microplasmas on-chips

任何电子器件中50%的材料都是用低压等离子体制造的，而常压等离子体是用来进行化学分析的，例如，电感耦合等离子体(ICP)就是元素分析中的主力。但ICP的购买和运营成本很高：典型的ICP是台式大小的，它消耗大约20Lit/分钟的昂贵Ar气体，它需要1-2千瓦的电力。电感耦合等离子体的温度也会达到10000 K左右，因此需要冷却。大气压微等离子体(即在亚毫米或微米范围内具有一个临界尺寸的等离子体)在科学文献中一直受到关注。与ICP相比，大气压芯片上的微等离子体消耗10-15瓦的电力(因此它们可以通过电池操作)，并且它们使用的是毫升/分钟的惰性气体，从而降低了运营成本。与“热”的电感耦合等离子体不同，微等离子体具有“冷”操作的耐人寻味的特性。这消除了冷却，使微等离子体能够在各种材料和技术上制造，例如，我们使用3D打印和塑料基板制造芯片上的微等离子体，从而减少了尺寸、重量和拥有成本。由于其体积小、重量轻，可以使微等离子体便携，因此可用于将实验室的一部分用于样品类型的应用(例如，用于现场分析测量)。 有关低温微等离子体的基础知识十分匮乏。我们不知道微等离子体是如何工作的(即，它们的激发机制是什么)，以及它们的基本等离子体参数(等离子体温度、等离子体中的电子浓度)如何随着操作条件的变化而变化。如果要改进芯片上微等离子体的分析性能特性，这些知识是必不可少的。这项建议是为进行这类研究所需的资金。基础的光谱诊断研究将有助于科学知识，因为冷微等离子体已被描述为“等离子体物理学的新领域”。就仪器对基础研究、科学和医学的历史贡献而言，正是各种显微镜向肉眼看不见的科学世界敞开了大门，也是许多类型的望远镜使宇宙研究成为可能。最近(2014)，诺贝尔化学奖因荧光显微镜的发展而获奖，诺贝尔物理学奖(2014)因蓝色发光二极管(LED)的发明而获奖--这两项显然都是仪器的发展。-- 本提案中所述的研究将为创新、发明和培训高素质人才创造难得的机会。参与研究的人员将获得的技能和知识将使他们能够与世界各地任何主要的学术、政府和工业实验室的人员竞争。

While low-pressure plasmas are used for fabrication of >50% of what goes into any electronic device, atmospheric pressure plasmas are used for chemical analysis, e.g., the ICP (Inductively Coupled Plasma) is a workhorse in elemental analysis. But ICPs are expensive to purchase and operate: a typical ICP is bench-top size, it consumes about 20 Lit/min of expensive Ar-gas and it uses 1-2 kWatt of electrical power. An ICP also gets ~10,000 K hot, thus requiring cooling.  Atmospheric-pressure microplasmas (i.e., those with one critical dimension in the sub-mm or micro-meter regime) have been receiving attention in the scientific literature. In contrast to ICPs, atmospheric-pressure microplasmas-on-chips consume 10-15 Watt of electrical power (thus they can be operated from a battery) and they use mL/min of an inert gas, thus reducing operating costs. And unlike their “hot” ICP counterparts, microplasmas have the intriguing property of operating “cold”. This eliminates cooling and enables microplasma-fabrication on a variety of materials and technologies, for instance, we fabricated microplasmas-on-chips using 3D-printing and plastic substrates, thus reducing size, weight and cost of ownership. Due to their small-size and light-weight microplasmas can be made portable, thus they can be used for taking part-of-the-lab to the sample type of applications (e.g., for analytical measurements on-site). Fundamental knowledge on cold microplasmas is scarce. We do not know how microplasmas work (i.e., what is their excitation mechanism) and how their fundamental plasma-parameters (plasma temperature, electron concentration in a plasma) vary with operating conditions. Such knowledge is essential if analytical performance characteristics of microplasmas-on-chips are to be improved. This proposal is for funds required to undertake such studies.  Fundamental spectroscopic diagnostic studies will contribute to scientific knowledge because cold microplasmas have been described as a “new realm in plasma physics”.   In terms of historical contributions of instruments to fundamental research and to science and to medicine, it is the variety of microscopes that opened-up to science worlds invisible to unaided eyes, and of the many types of telescopes that enabled study of the universe. More recently (2014), the Nobel prize for Chemistry was awarded for the development of fluorescence microscopy and the Nobel Prize for Physics (2014) was awarded for the invention of the blue light emitting diode (LED)-both of these are clearly instrument developments.   Research described in this proposal will create exceptional opportunities for innovation, invention and for the training of highly qualified personnel. The skills and knowledge to be obtained by participating researchers will allow them to compete with those from any major academic, government and industrial lab worldwide.