CAREER: Giant Tunability through Piezoelectric Resonant Acoustic Metamaterials for Radio Frequency Adaptive Integrated Electronics

我们的福祉和生计、教育、社会交往以及基础科学知识越来越依赖于云存储、边缘计算、机器学习、人工智能（AI）和第五代（5G）无线通信等一系列先进技术。然而，为了使这些技术取得成功，新的硬件组件，如基于新材料和技术的更稳定的频率合成器（FSs）将是至关重要的，需要开发。同样，物联网（IoT）在已经拥挤的频谱中创建了越来越多的无线节点。因此，需要新的低功耗可调前端架构，能够过滤干扰信号并适应不断变化的电磁场景，以实现更高的通信吞吐量和更长的电池寿命。为了应对这些挑战，本CAREER提出开发一类新的无源、可调谐和高性能集成谐振器件，即压电谐振声学超材料（pRAMs）。由于其独特的、人工生产的和可重构的模态特征，pram的开发将使新的稳定的FSs、物联网无线电的自适应前端和许多其他片上传感器用于传感和通信。该项目团队将与东北大学STEM教育中心合作，组织校园活动，以及与当地学校和社区中代表性不足的群体建立联系的外展访问。该项目的成果将丰富首席研究员教授的电路理论和先进的基于声学的通信和传感技术的本科和研究生课程。pram将依赖于声学超材料的独特传播特性，由cmos兼容的氮化铝（AlN）或氮化铝钪（AlScN）薄膜制成，并体现了磁致伸缩棒的周期性排列。由于其独特的、人工制造的和可重构的模态特性，pram将超越阻碍低损耗声学谐振技术实现的材料限制，即使在中等频率调谐范围内也是如此。这将允许创建新的基于片上声学的无源，并将为未来的网络组件提供更稳定的FSs。此外，pram将允许开发新型可调谐通道选择滤波器，使未来几代物联网无线节点能够抵御干扰并消耗更低的功耗。可以设想，通过利用其新的磁敏行为负责其大调谐范围，pram可能会为新型芯片级磁强计铺平道路，实现低检测极限，以满足关键生物磁学和环境应用的挑战性需求，但不需要偏压或冷却。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Our well-being and livelihood, our education, our social interactions, and our knowledge of the fundamental sciences depend, more and more, on a host of advanced technologies, such as cloud-storage, edge-computing, machine learning, artificial intelligence (AI) and fifth-generation (5G) wireless communication. However, to allow these technologies to succeed, new hardware components such as more stable frequency synthesizers (FSs) based on novel materials and techniques will be critical and need to be developed. Similarly, the Internet-of-Things (IoT) has created a growing number of wireless nodes within an already congested spectrum. Therefore, new lower-power tunable front-end architectures that are capable of filtering interference signals and adapting to changing electromagnetic scenarios are needed to grant higher communication throughputs and longer battery lifetimes. To meet these challenges, this CAREER proposes to develop a new class of passive, tunable, and high-performance integrated resonant devices, namely the Piezoelectric Resonant Acoustic Metamaterials (pRAMs). Thanks to their unique, artificially produced and reconfigurable modal features, the development of pRAMs will enable new stable FSs, adaptive front ends for IoT radios and many other on-chip transducers for sensing and communication. The project team will collaborate with the Northeastern University’s Center for STEM Education to organize on-campus activities, as well as outreach visits to connect with underrepresented groups in local schools and communities. The project achievements will enrich both the undergraduate and the graduate courses that the Principal Investigator teaches on circuit theory and on advanced acoustic-based technologies for communication and sensing. The pRAMs will rely on the distinctive propagation features of acoustic metamaterials, built out of CMOS-compatible Aluminum Nitride (AlN) or Aluminum Scandium Nitride (AlScN) thin-films and embodying a periodic arrangement of magnetostrictive rods. Thanks to their unique, artificially produced and reconfigurable modal characteristics, pRAMs will surpass the material limitations that have prevented the achievement of low-loss acoustic resonant technologies, even with moderate frequency tuning ranges. This will allow the creation of new on-chip acoustic-based passives and will provide the means to achieve significantly more stable FSs for future networking components. Furthermore, pRAMs will allow the development of a new class of tunable channel-select-filters enabling future generations of IoT wireless nodes resilient to interference and consuming lower power. It is envisioned that by exploiting their new magnetosensitive behavior responsible for their large tuning range, pRAMs will likely pave the way towards a new class of chip-scale magnetometers, achieving the low limits of detection compatible to the challenging needs of critical biomagnetic and environmental applications, yet not requiring to be biased or cooled.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.