Seamless low-power omnimedium communication via piezoelectricity

Abstract

The forthcoming 6G wireless network aims to deliver universal accessibility, ultra-high-speed connectivity, and low latency, fully integrating the global Internet of Everything (IoE). This ambitious goal necessitates the seamless integration of networks across diverse domains and mediums, including space, air, subterranean, in-body, in-solid, and underwater environments. Supported by this expansive vision, we propose the concept of omnimedium communication, which is centered on achieving seamless, low-power data transmission intra or across a wide variety of physical environments, transcending traditional communication barriers. With omnimedium communication, a wide range of modern societal applications becomes feasible, such as structural health monitoring (SHM) within concrete walls, soil environment surveillance, undersea exploration, and biometric monitoring within the human body. Despite some progress in communication within non-aerial mediums and across different mediums, existing communication systems often grapple with issues such as lack of robustness, high energy consumption, and substantial size. This thesis introduces two innovative, piezoelectric-based communication paradigms designed to address these challenges. The first paradigm exploits the acoustic-electrical conversion properties of piezoelectric materials to develop passive intra-medium acoustic backscatter communication modules. The second paradigm employs the capacity of piezoelectric materials to radiate electromagnetic (EM) waves, facilitating the design of compact units capable of efficient cross-medium communication. The first study introduces self-sensing concrete embedded with EcoCapsules, a novel battery-free, miniature piezoelectric backscatter node. This technology meets the critical demand for persistent SHM in civilian buildings, surmounting obstacles presented by wired connections and frequent battery replacement. By incorporating EcoCapsules within concrete structures, we establish robust in-concrete backscatter communication with notable throughput and energy harvesting capabilities, as demonstrated through comprehensive real-world testing. The second study features MeAnt, a versatile IoT platform that enables cross-medium communication through piezoelectric-based mechanical antennas. This platform ensures seamless communication across various environments, such as air, water, soil, concrete, and biological tissues, exploiting the propagation characteristics of medium-frequency radios. MeAnt tackles prevalent issues such as interference from AM broadcasts and the inherent unidirectional nature of Piezo-MAs, employing a meticulously developed full-stack communication protocol that has proven effective, showcasing significant penetration depth and throughput in diverse environmental conditions. Collectively, these studies underscore the transformative potential of piezoelectric materials in fostering seamless, low-power omnimedium communication. They provide groundbreaking solutions for intra-concrete SHM and establish versatile networks capable of operating across multiple mediums. These findings illustrate the adaptability and efficiency of piezoelectric technologies in omnimedium communication systems, paving the way for innovative applications and enhanced connectivity in diverse environments.