Acoustic energy transfer for wireless charging of low-power sensors, control devices, and communication networks

不使用物理插头或电线的能量传输，被称为非接触式能量传输，是一项具有无限应用潜力的变革性技术。它特别适用于有线电接触危险或不切实际的应用。此外，在有线连接或更换电池不实际或可能不可行的应用（例如医疗植入物）中，它将加强低功率传感器、控制设备和通信网络的开发、使用和可靠性，增加与系统设计和操作相关的复杂性（例如家庭、汽车和飞机）或可能造成自身危险（例如火灾危险）。作为非接触式能量传输方法（即感应方法）的替代方案，超声波声能传输基于以超声波频率向压电接收器传播的声波，为无线充电系统提供了增加发射器-接收器距离的潜力，减少了功率损耗，消除了与电磁场相关的危害。该奖项支持基础研究，以建立一个实验验证的数学框架，用于在广泛的低到高电和声激励水平范围内受到声介质时压电传输和接收的声-电弹性动力学。提出的实验和分析多物理场建模方法旨在填补在考虑超声声能传递系统中与高激励水平相关的非线性效应方面的知识空白。这些影响包括耦合的非线性声场与非保守的电弹性结构响应，以及由于阻抗不匹配导致的反射，导致空间共振，能量损失和波在非线性色散介质中传播时出现高次谐波。这项研究将导致对共振声压电系统的新理解，这将影响各种应用的超声波声波能量传递系统的设计——通过一种基于声学的新型能量传递系统的低功率传感器无线充电的创新机制，选择性和非侵入性。研究团队将在基础层面提供建议，通过解决不同换能器设计的功率输出，电阻和电阻无功负载，声阻抗匹配层以及材料和非线性效应来提高系统性能。研究成果将有助于设计最佳声学系统，在各种应用中以更高的效率传递更高的功率水平。该项目还将通过与弗吉尼亚理工大学工程多样性增强中心合作制定的互补和引人入胜的教育计划，接触并激励大量代表性不足和少数民族的学生。

Energy transfer without the use of physical plugs or wires, referred to as contactless energy transfer, is a transformative technology with potentially endless applications. It is particularly relevant in applications where wired electrical contact is dangerous or impractical. Furthermore, it would enhance the development, use and reliability of low-power sensors, control devices and communication networks in applications where wired connections or changing batteries are not practical or may not be a viable option (e.g. medical implants), add to the complexities associated in the systems design and operation (e.g. homes, cars and airplanes) or may pose their own hazards (e.g. fire hazard). As an alternative to the relatively well-studied method of contactless energy transfer, namely the inductive method, ultrasonic acoustic energy transfer, which is based on the propagation of acoustic waves at ultrasonic frequencies to a piezoelectric receiver, offers the potential for wireless charging systems over increased transmitter-receiver distances, with reduced power losses, and elimination of hazards associated with electromagnetic fields. This award supports fundamental research to establish an experimentally-validated mathematical framework for the acoustic-electroelastic dynamics of piezoelectric transmission and reception when subjected to an acoustic medium over broad ranges of low-to-high electrical and acoustic excitation levels. The proposed experiments and analytical multiphysics modeling approach aim at filling a knowledge gap in terms of considering nonlinear effects associated with high excitation levels in ultrasound acoustic energy transfer systems. These effects include the coupled nonlinear acoustic field with non-conservative electroelastic structural responses along with reflections due to impedance mismatch that lead to spatial resonances, energy loss and appearance of higher harmonics during wave propagation in a nonlinear dispersive medium. This research will lead to new understanding of resonant acoustic-piezoelectric systems that will influence the design of ultrasonic acoustic energy transfer systems for various applications -- through innovative mechanisms for wireless charging of low-power sensors by an acoustic-based novel power delivering system, selectively and noninvasively. The research team will provide recommendations at the fundamental level for enhancing system performance through addressing power output for different transducer designs, resistive and resistive-reactive loading, acoustic impedance matching layers, and the material and nonlinearity effects. The output of the research effort will help in the design of optimal acoustic systems that can transfer higher power levels at higher efficiencies in various applications. This project will also reach and inspire a large number of underrepresented and minority students through a complementary and engaging educational plan, prepared in collaboration with Center for Enhancement of Engineering Diversity at Virginia Tech.