Dynamics of Contactless Ultrasonic Power Transfer for Wireless Devices

在过去的十年中，已经大量研究了将诸如振动能的环境机械能转换成低功率电力以实现自供电无线电子部件。只要在小型设备附近容易获得足够的环境能量，这种能量转移方法就是可能的。有几种情况下，没有可用的环境能量或电池更换或系绳充电是不可取的或不可能的，例如，位于危险环境中的深植入医疗设备或传感器，如核废料容器。在这种情况下，需要非接触式电力传输。这项理论和实验研究的主要目标是对非接触式超声功率传输动力学进行系统级研究，为其在下一代无线设备中的实现奠定基础。最近受到越来越多关注的非接触式电力传输的一种特定方法是使用超声波（其是频率高于人类听觉范围的声波）。与诸如电感耦合的流行功率传输方法相比，超声波的使用提供了若干优点，诸如使用较小的换能器的相对长的功率传输距离，以及消除磁场。这项研究具有重大的技术潜力和广泛的社会影响。无线电子元件的非接触式供电可以减少传感器网络的维护成本和废弃电池的化学废物。深度植入医疗设备的无线充电可以消除与电池更换相关的手术相关并发症。该项目包括努力招收女大学生和少数民族大学生，并让高中教师参与研究工作。 由于存在障碍物、反射、衍射、损耗以及由所涉及的多个域引起的声学或机电阻抗匹配问题，超声波功率传输作为无线应用中的使能技术的有效使用面临困难的挑战。本研究计划的目标是通过耦合机电系统，压电，超声波物理和声学超材料的动力学，对非接触式超声功率传输进行系统级的理论和实验研究。 该项目将产生一个全面的知识，基本的多物理场动力学将被利用在下一代无线电子设备，从医疗植入物到远程传感器，没有直接的物理访问。将联合收割机发射器-接收器-电负载动态与跨多个域的声传播相结合的系统级、实验验证的高保真度多物理场建模框架可以实现高效超声功率传输系统的设计。此外，来自声子晶体和超材料的概念可以用于组合波聚焦和阻抗匹配，并且相控阵列可以用于电力传输中的障碍规避。具体的研究目标是（1）建立完全耦合的建模框架，以分析非接触式超声功率传输的多物理场动力学;（2）利用各种压电发射器-接收器架构，包括相控阵列;（3）利用声子晶体和超材料进行组合波聚焦和阻抗匹配。

The transformation of ambient mechanical energy such as vibrational energy into low-power electricity for enabling self-powered wireless electronic components has been heavily investigated over the last decade. This method of energy transfer is possible as long as sufficient ambient energy is readily available in the vicinity of small devices. There are several conditions where there is no ambient energy available or battery replacement or tethered charging is either undesirable or impossible, for example, deep-implanted medical devices or sensors located in hazardous environments such as nuclear waste containers. In such cases, contactless power transfer is needed. The primary objective of this theoretical and experimental research is to perform a system-level investigation of contactless ultrasonic power transfer dynamics to lay the foundation for its implementation in next-generation wireless devices. One particular method of contactless power transfer that has lately received growing attention is the use of ultrasound waves (which are acoustic waves with frequencies higher than the human hearing range). The use of ultrasound offers several advantages such as relatively long power transmission distances using smaller transducers, and elimination of magnetic fields, as compared to popular power transfer methods such as inductive coupling. The research has significant potential for technological and broad societal impact. Contactless powering of wireless electronic components can reduce the maintenance costs in sensor networks and chemical waste of discarded batteries. Wireless charging of deep-implanted medical devices can eliminate the surgery-related complications associated with battery replacement. The project involves efforts to recruit women and minority undergraduate students and involvement of high school teachers in research experience. The effective use of ultrasonic power transfer as an enabling technology in wireless applications faces difficult challenges due to the presence of obstacles, reflections, diffractions, losses, and acoustic or electromechanical impedance matching issues resulting from the multiple domains involved. The objective of this research program is to perform a system-level theoretical and experimental investigation of contactless ultrasonic power transfer by coupling the dynamics of electromechanical systems, piezoelectricity, ultrasonic wave physics, and acoustic metamaterials. The project will generate a comprehensive knowledge of the underlying multiphysics dynamics to be exploited in next-generation wireless electronic devices spanning from medical implants to remote sensors with no direct physical access. System-level, experimentally validated, high-fidelity multiphysics modeling frameworks that combine transmitter-receiver-electrical load dynamics with acoustic propagation across multiple domains can enable the design of efficient ultrasonic power transfer systems. Additionally, concepts from phononic crystals and metamaterials can be exploited for combined wave focusing and impedance matching, and phased arrays can be leveraged for obstacle circumventing in power transfer. The specific research goals are to (1) establish fully coupled modeling frameworks to analyze multiphysics dynamics of contactless ultrasonic power transfer; (2) leverage various piezoelectric transmitter-receiver architectures including phased arrays; and (3) exploit phononic crystals and metamaterials for combined wave focusing and impedance matching.