Microfluidic Devices for Tunable RF Communication Systems

可重新配置的射频天线和电路已经以几种方式实现，包括使用MEMS开关、可变阻抗元件或操纵地平面。没有一种单一的解决方案能够实现低损耗、敏捷性、低成本和可靠性等所有期望的品质。提出了一种新的方法，涉及液体-金属微流控技术，通过在平面上移动金属来几何地重新配置天线和电路。其目的是利用液态金属的微流体驱动，使射频设备的调谐像使用蚀刻素描玩具绘制图案一样简单。所提出的方法将用在室温下是液态的金属，例如汞或镓合金来代替典型的铜微带元件。这些液态金属可以回流形成不同形状和大小的导电元件，从而导致射频电路的调谐。微流控技术可精确控制微小液体体积，并已广泛应用于生物医学设备等领域。微流体的功能将扩展到包括可调谐的射频设备。为了最大限度地提高流体驱动的灵活性和速度，同时最大限度地减少对射频组件的干扰，将使用电润湿和压力驱动流动的流体驱动来制造使用液态金属的可调射频器件。智能优点本提案的研究目标是使用微流体驱动来实现使用动态、灵活的液态金属射频元件图案化的射频设备的调谐。使用2D嵌入式电极阵列或专门设计的微通道，可以动态地排列各种形状和大小的液态金属。该方法可用于对构成天线、滤波器、匹配网络和耦合结构基础的平面传输线单元进行几何重构。在这项提案中，将通过为射频过滤器的自主、高方向性波束导向和可调频率选择表面创建可调反射阵列来展示液态金属图案化的能力。拟议的研究结果将对射频系统设计者和射频社区有价值。广泛影响实现这种灵活、可重新配置的组件的更广泛的影响是巨大的，影响商业、科学、政府和军事应用。拟议的研究将使系统变得更加通用、多功能、健壮和经济。最近，对广泛的、负担得起的、可访问的宽带无线网络的需求被确定为这个国家的关键经济驱动力之一，而拟议的研究是朝着实现这一目标迈出的一步。此外，这项提案将重点关注代表人数不足的少数群体参与研究生和本科生水平的研究项目。夏威夷土生土长的工程学学生将被鼓励作为学生研究人员参与这项拟议的研究。与拟议研究相关的概念将以一种引人入胜的方式介绍，通过开放参观和在当地学校授课，激发K-12学生对科学和工程的兴趣。

Reconfigurable RF antennas and circuits have been implemented in several ways including the use of MEMS switches, variable impedance elements, or manipulation of the ground plane. No single solution achieves all the desired qualities of low loss, agility, low cost, and reliability. A new approach is proposed that involves liquid-metal microfluidic technology for geometrically reconfiguring antennas and circuits by literally moving metal across a planar surface. The aim is to use microfluidic actuation of liquid metals to make the tuning of RF devices as straightforward as drawing patterns using an Etch-A-Sketch toy. The proposed approach will replace typical copper microstrip components with a metal that is liquid at room temperature, such as mercury or gallium alloys. These liquid metals can reflow to form conductive elements of varying shapes and sizes, resulting in a tuning of the RF circuit. Microfluidic technology provides precise control of small liquid volumes, and has been widely developed for applications such as biomedical devices. The functionality of microfluidics will be extended to include tunable RF devices. To maximize flexibility and speed of fluidic actuation while minimizing interference with RF components, fluid actuation using electrowetting and pressure-driven flow will be used to create tunable RF devices using liquid metals.Intellectual MeritThe research objective of this proposal is to use microfluidic actuation to enable the tuning of RF devices using dynamic, flexible patterning of liquid metal RF elements. Using a 2D embedded electrode array or specially designed microchannels, it will be possible to dynamically pattern liquid metals in all types of shapes and sizes. The proposed approach can be used for geometrically reconfiguring planar transmission line elements that form the basis of antennas, filters, matching networks, and coupling structures. In this proposal, the capabilities of liquid-metal patterning will be demonstrated by creating tunable reflectarrays for autonomous, high-directivity beamsteering and tunable frequency-selective surfaces for RF filters. Results of the proposed research will be valuable to RF system designers and the RF community.Broader ImpactsThe broader impacts of realizing such agile, reconfigurable components are huge, impacting commercial, scientific, government, and military applications. The proposed research will enable systems that are more versatile, multifunctional, robust, and economical. Recently a need has been identified for a widespread, affordable, and accessible broadband wireless networks as one of the key economic drivers for this nation, and the proposed research is a step towards realizing this goal. In addition, this proposal will strongly focus on the participation of underrepresented minorities in graduate- and undergraduate-level research projects. Native Hawaiian engineering students will be encouraged to participate as student researchers for the proposed research. Concepts related to the proposed research will be introduced in an engaging manner to pique interest in science and engineering among K-12 students via open houses and lectures at local schools.