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

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.