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

我们的福祉和生计、我们的教育、我们的社会互动以及我们对基础科学的知识越来越依赖于一系列先进技术，如云存储、边缘计算、机器学习、人工智能(AI)和第五代(5G)无线通信。然而，为了使这些技术获得成功，基于新材料和新技术的更稳定的频率合成器(FSS)等新的硬件组件将是关键，需要开发。同样，物联网(IoT)在本已拥塞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，这一职业提出了开发一类新型的无源、可调和高性能的集成谐振器件，即压电谐振声学超材料(PRAM)。由于其独特的、人工产生的和可重新配置的模式特征，PRAM的开发将使新的稳定的FSS、物联网无线电的自适应前端以及许多其他用于传感和通信的片上换能器成为可能。该项目团队将与东北大学STEM教育中心合作，组织校园活动，以及外联访问，以联系当地学校和社区中代表不足的群体。项目成果将丰富首席调查员教授的电路理论和先进的以声学为基础的通信和传感技术的本科生和研究生课程。PRAM将依靠声学超材料的独特传播特性，这些超材料由与CMOS兼容的氮化铝(AlN)或氮化铝(AlScN)薄膜制成，体现了磁致伸缩棒的周期性排列。由于其独特的、人工制造的和可重新配置的模式特性，PRAM将超越阻碍实现低损耗声学共振技术的材料限制，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声学的无源芯片，并将为未来的网络组件提供实现更稳定的FSS的手段。此外，PRMS将允许开发一类新的可调频道选择过滤器，使下一代物联网无线节点具有抗干扰能力，并消耗更低的功率。据设想，通过利用其大调谐范围的新磁敏行为，PRAM可能会为新一类芯片级磁强计铺平道路，实现与关键生物磁学和环境应用的挑战性需求兼容的低检测下限，而不需要偏置或冷却。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.