CAREER: Novel Microplasmas for Highly Compact and Versatile RF Electronics

由于频谱日益拥挤和竞争激烈，可重构RF电子器件已成为广泛研究的主题。半导体器件、微机电系统（MEMS）、液晶和铁磁材料通常用作RF调谐的工具。然而，这些技术受到有限的调谐范围和低功率处理能力的限制。为了克服这些限制，冷等离子体提出了一个有前途的解决方案。操纵内部参数，如电子密度，气体类型和压力，提供了广泛的等离子体电磁特性的可调性。冷等离子体已经在各种与社会相关的应用中提供了显著的优势，例如等离子体医学、食品保存、水处理、等离子体肥料、电推进系统、灭菌和半导体制造。这项研究探索了基础物理学，并展示了建立稳定的微等离子体的技术，这些微等离子体具有特殊的电磁特性，可用于多功能RF电子设备。为了实现这一愿景，（1）将开发高频微等离子体的理论和建模框架，（2）将研究闭环微等离子体监测和控制系统，（3）将实现具有前所未有的电磁特性的稳定微等离子体。本科生和研究生将参与，一个独特的教育等离子体实验室将建立，并将开发基于电路的电磁等离子体模拟器。此外，还将开展各种协同外联活动，包括为任职人数不足的学生举办托莱多Excel夏令营。通过结合创新的研究，教育计划和推广工作，这一奋进旨在推进可重构RF电子学的发展，为新兴的多目标和多频率系统铺平道路。等离子体代表了可以在纳秒时间尺度上控制的快速可重构介质。微等离子体和电磁波之间的相互作用引入了一个新的重要应用领域，可以归类为“气体微电子学”。“这项研究旨在通过探索能够与电磁波进行非常规相互作用的可广泛调谐微等离子体来推动等离子体科学的边界。这种特殊的行为将通过对微等离子体动力学的基本理解和精确控制来实现。虽然在基于等离子体的射频电子学方面已经做出了一些努力，但这一研究领域尚未得到全面探索，特别是对于具有极端电磁特征的微等离子体，这是该项目旨在解决的知识差距。为了实现这一总体目标，将开发一种新的闭环控制系统，包括创新的诊断技术，以准确地操纵微等离子体。通过所有的理论、数值和实验研究，目标是实现（i）具有非凡可调谐性的高Q微等离子体变容管，（ii）自然的ε近零（ENZ）微等离子体，以及（iii）低损耗负折射率材料（NIM）。目前还不存在用于高频调谐的快速和广泛可调谐、低损耗和高功率材料，但这项研究可以改变这种模式。通过利用这些独特的材料，可以实现更有效地利用电磁频谱，有效地满足对无线服务不断增长的需求。此外，这些功能将有利于新兴的传感，生物医学和空间应用，解决这些领域的关键需求，促进技术创新。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Due to the increasingly congested and contested spectrum, reconfigurable RF electronics have become a subject of extensive research. Semiconductor devices, microelectromechanical systems (MEMS), liquid crystals, and ferromagnetic materials have conventionally served as tools for RF tuning. However, these technologies are constrained by limited tuning ranges and low power handling capabilities. To overcome these limitations, cold plasma presents a promising solution. Manipulating internal parameters, such as electron density, gas type, and pressure, offers extensive tunability over plasma electromagnetic properties. Cold plasmas have already provided significant advantages across various societally relevant applications, such as plasma medicine, food preservation, water treatment, plasma fertilizer, electric propulsion systems, sterilization, and semiconductor fabrication. This research explores fundamental physics and demonstrates techniques for establishing stable microplasmas with exceptional electromagnetic properties for versatile RF electronics. To realize this vision, (1) theoretical and modeling frameworks for high-frequency microplasmas will be developed, (2) a closed-loop microplasma monitoring and control system will be investigated, and (3) stable microplasmas with unprecedented electromagnetic features will be realized. Undergraduate and graduate students will be involved, a unique educational plasma lab will be established, and a circuit-based electromagnetic-plasma simulator will be developed. In addition, various synergistic outreach activities will be conducted, including Toledo Excel summer camps for underrepresented students. By combining innovative research, educational initiatives, and outreach efforts, this endeavor aspires to advance the landscape of reconfigurable RF electronics, paving the way for emerging multi-objective and multi-frequency systems.Plasmas represent rapidly reconfigurable media that can be controlled on nanosecond timescales. The interaction between microplasmas and electromagnetic waves introduces a new field of significant applications that can be categorized as "Gaseous Microelectronics." This study aims to push the boundaries of plasma science by exploring widely tunable microplasmas capable of unconventional interactions with electromagnetic waves. This exceptional behavior will be achieved through fundamental understanding and precise control of microplasma kinetics. While some efforts have been made in plasma-based RF electronics, this research field has not yet been comprehensively explored, specifically for microplasmas with extreme electromagnetic features—a knowledge gap this project aims to address. To pursue this overarching objective, a novel closed-loop control system, including innovative diagnostic techniques, will be developed to accurately manipulate microplasmas. With all theoretical, numerical, and experimental investigations involved, the goal is to realize (i) high-Q microplasma varactors with extraordinary tunability, (ii) natural epsilon-near-zero (ENZ) microplasmas, and (iii) low-loss negative index materials (NIMs). Rapidly and widely tunable, low-loss, and high-power materials for high-frequency tuning do not currently exist, but this research can change this paradigm. By leveraging these unique materials, more efficient utilization of the electromagnetic spectrum can be achieved, effectively meeting the escalating demand for wireless services. In addition, these features will benefit emerging sensing, biomedical, and space applications, addressing critical needs in these domains and fostering technological innovations.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.