• Energy Research

Abstract The capability of using a linear kinetic energy harvester – A cantilever structured piezoelectric energy harvester – to harvest human motions in the real-life activities is investigated. The whole loop of the design, simulation, fabrication and test of the energy harvester is presented. With the smart wristband/watch sized energy harvester, a root mean square of the output power of 50 μW is obtained from the real-life hand-arm motion in human’s daily life. Such a power is enough to make some low power consumption sensors to be self-powered. This paper provides a good and reliable comparison to those with nonlinear structures. It also helps the designers to consider whether to choose a nonlinear structure or not in a particular energy harvester based on different application scenarios.

Solid-rotor induction machines have gained significant attention in various industrial applications due to their robustness, reliability, and cost-effectiveness. This paper presents a comprehensive overview of these machines, covering their classification and various applications. The paper starts with discussing the widespread usage of solid-rotor induction machines in numerous industry sectors, including manufacturing, transportation, and renewable energy generation. The ability to operate under harsh environmental conditions and in safety-critical settings has made these machines indispensable in many fields of engineering. Their detailed classification based on different rotor topologies is provided, highlighting the unique design features and performance characteristics of each category. Simple and hybrid configurations and their distinct advantages and limitations in specific applications are included. This paper further explores the essential aspects of multi-physics modeling of solid-rotor induction machines, incorporating electromagnetic, mechanical, and thermal considerations to gain deep insights into the complex interactions between components and to guide the optimization process for enhanced performance and efficiency. This work is intended as a valuable reference for researchers and engineers seeking a comprehensive understanding of solid-rotor induction machines, from their diverse applications to the intricacies of their electromagnetic, thermal, and mechanical modeling. By shedding light on these aspects, this work contributes to the advancement and utilization uptake of these machines in modern industrial settings.