Integrating High Frequency Whispering-Gallery-Mode Phononic Cavities with Efficient Electrically-Small Antennas: Pushing the Limits of Wireless Passive Micro-Sensing

该项目旨在探索和联合收割机新颖的微尺度谐振器设计与极小的天线相结合，以构建一个无线传感平台，该平台不需要电源，并利用经济规模，以非常低的价格点提供卓越的性能。该平台一旦实现，被认为将通过提供远程和非侵入式测量患者生命体征的灵活性，对医学传感范式产生重大影响。尽管在过去几十年中在微电子领域中取得了巨大的技术进步，但是在医疗行业中使用的感测设备的规模与小型化传感器领域中的最新技术水平之间存在差距。具体而言，监测呼吸率和呼吸模式的设备由于过多的布线而对患者不方便。该项目中提出的平台可以显著缩小监测呼吸率所需设备的尺寸。相同的技术可以适用于连续监测温度（包括核心体温）、心率、血压、氧气摄入量等，而无需更换电池。数据收集可以通过一个简单的小工具来实现，这个小工具可以与智能手机通信。主要研究人员正在参加NSF支持的青年企业家和学者职业发展辅导计划（CAMP-YES）以及中央佛罗里达大学的研究和辅导活动（拉马）计划，这两项计划都促进了代表性不足的本科生的研究经验。本项目开发的资源将通过招募学生参与本研究，帮助主要研究人员进一步为这些项目做出贡献。 该项目的主要目标是通过探索与超小型高效天线集成的超高品质因数（Q）压电高频谐振器，实现超小型无线无源传感器。在这项工作中，第一次，回音壁模式声子腔的压电超纳米晶金刚石平台将被证明与实现高耦合因子和高品质因子在1 GHz左右的高频的目标。选择回音壁模式以避免锚损失（能量损失的主要来源），并且选择金刚石衬底以最小化高频下的内部摩擦损失的影响。如此大的耦合和Q值可以实现具有几米的读出范围的极小尺寸（包括天线的lcm X lcm）的无线传感器。这些任务包括：1）研究了高频金刚石基压电陶瓷谐振器的损耗物理; 2）在金刚石基压电陶瓷薄膜平台上实现了回音壁模式的声子腔; 3）将声子腔与高效电小天线集成，开发了无源无线传感器。这样的传感器可以比在类似频率下操作的其他无线传感器小几个数量级。该项目中的超小型无线传感器的成功演示将对广泛的遥感应用产生重大影响，包括医疗健康监测和诊断、环境监测和工业控制。

This project aims to explore and combine novel micro-scale resonator designs with extremely small antennas to build a wireless sensing platform that does not require power sources and takes advantage of the economy scale in delivering exceptional performance at very low price-points. This platform, once realized, is believed to make a significant impact on medical sensing paradigms by offering flexibility in remote and nonintrusive measurement of patients vital signs. Despite the tremendous technological progress made in the field of microelectronics during the past few decades, there exists a gap between the scale of sensing apparatus used in medical industry and the state-of-the-art in the field of miniaturized sensors. Specifically, the devices monitoring respiration rate and breathing pattern are inconvenient for the patients due to excessive wiring. The platform proposed in this project can significantly scale down the size of the equipment required for monitoring breathing rate. The same technology can be adapted for continuous monitoring of the temperature (including the core body temperature), the heart rate, blood pressure, oxygen intake, etc. without the need for changing the battery. The data collection can be achieved by a simple and small gadget that could communicate with smartphones. The principal investigators are participating in the NSF-supported Career Advancement Mentoring Program for Young Entrepreneur and Scholars Program (CAMP-YES) and the Research and Mentoring Activities (RAMA) program at the University of Central Florida, both of which promote research experience for underrepresented undergraduate students. The resources developed in this project will assist the principal investigators in furthering their contributions to these programs by recruiting students to engage in this research. The main objective of this project is to enable extremely-small wireless passive sensors by exploring exceptionally high quality factor (Q) piezoelectric-based high-frequency resonators integrated with ultra-small highly-efficient antennas. In this work, for the first time, whispering-gallery mode phononic cavities in a piezoelectric-on-ultrananocrystalline diamond platform will be demonstrated with the goal of achieving high coupling factor and high quality factor at high frequencies around 1 GHz. The whispering gallery mode is chosen to evade the anchor-loss (a major source of energy loss) and the diamond substrate is chosen to minimize the effect of internal friction losses at high frequencies. Such large values of coupling and Q could enable extremely-small size ( 1 cm x 1 cm including the antenna) wireless sensors with a readout range of a few meters. The tasks include: 1) Studying the physics of loss in high frequency piezoelectric-on-diamond resonators, 2) Implementation of whispering-gallery mode phononic cavities in the thin-film piezoelectric-on-diamond platform, 3) Integration of the phononic cavities with highly-efficient electrically-small antennas to develop passive wireless sensors. Such sensors can be orders of magnitude smaller than other wireless sensors operating at similar frequencies. Successful demonstration of extremely small wireless sensors targeted in this project will have a significant impact on a wide range of remote sensing applications including medical health monitoring and diagnosis, environmental monitoring, and industrial control.