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This study introduces an innovative asymmetric tri-stable piezoelectric vibration energy harvester (ATPVEH) augmented with an elastic base (EB), aimed at optimizing energy capture from low-orbit vibrations. This design incorporates a uniquely configured asymmetric tri-stable piezoelectric cantilever beam, positioned within a U-shaped block that is further enhanced by an elastic base. A strategically placed spring (kf)–mass (Mf) system, situated between the U-shaped block and the constrained end of the beam, significantly boosts the vertical displacement of the beam during vibrational events. We developed a dynamic model for the ATPVEH+EB utilizing Lagrange's equations, exploring the impact of various factors—including the asymmetry of the potential well, the stiffness of the elastic base, the mass of the spring–mass system, and the load resistance—on the system's nonlinear dynamic responses. Our findings indicate that the ATPVEH+EB facilitates more efficient energy harvesting from low-orbit vibrations, demonstrating dual response peaks across its operational frequency spectrum. Notably, the displacement and output voltage amplitudes of the ATPVEH+EB can be enhanced by increasing mf or decreasing kb, whereas the peak output power transitions toward a lower frequency range as the load resistance escalates. Both theoretical analyses and numerical simulations corroborate the ATPVEH+EB's superior performance in harvesting energy within low-orbit vibrational environments. [ABSTRACT FROM AUTHOR]

This paper proposes an asymmetric hybrid tri-stable piezoelectric energy harvester for rotational motion (RHTPEH). The device features an asymmetric tri-stable piezoelectric cantilever beam positioned at the edge of a rotating disk. This beam is uniquely configured with an asymmetric arrangement of magnets. Additionally, an elastic amplifier composed of a vertical and a rotating spring connects the beam's fixed end and the disk. This setup enhances both the rotational amplitude and vertical displacement of the beam during motion. A comprehensive dynamical model of the RHTPEH was developed using Lagrange's equations. This model facilitated an in-depth analysis of the system's behavior under various conditions, focusing on the influence of key parameters such as the asymmetry in the potential well, the stiffness ratio of the amplifier springs, the radius of the disk, and the disk's rotational speed on the nonlinear dynamic response of the system. The results show that the asymmetric hybrid tri-stable piezoelectric energy harvester makes it easier to harvest the vibration energy in rotational motion and has excellent power output performance compared with the symmetric tri-stable piezoelectric energy harvester. The output power magnitude of the system at higher rotational speeds increases as the radius of rotation expands, but when the rotational speed is low, the steady-state output power magnitude of the system is not sensitive to changes in the radius of rotation. Theoretical analysis and numerical simulations validate the effectiveness of the proposed asymmetric RHTPEH for energy harvesting in low-frequency rotating environments. [ABSTRACT FROM AUTHOR]

Piezoelectric energy harvesting faces a primary challenge in effectively capturing low-orbit vibration energy across a broad frequency range. In this paper, we present a tri-stable piezoelectric energy harvester that incorporates a dynamic amplifier (TPEH + DM), specifically designed for efficient collection of low-orbit vibration energy. The TPEH + DM comprises a piezoelectric cantilever beam connected to an innovative dynamic amplifier at its restrained end, which enhances both the rotational and lateral displacement of the piezoelectric cantilever beam simultaneously. The governing coupled differential equations of motion for the system is derived based on the Lagrange equation, and analytical expressions for its steady-state response are obtained using the multi-scale method. The influence of factors such as the mass and the stiffness ratio of the dynamic amplifier on the steady-state dynamic output characteristics of the system is investigated using the theoretical analysis and numerical simulation. The results indicate that TPEH + DM exhibits significantly improved energy harvesting performance compared to TPEH under low-orbit external excitations. The bandwidth of inter-well motion and the TPEH + DM power output may be further increased by suitably modifying the relative stiffness between the cantilever beam and the dynamic amplifier. In addition, we analyze the time-domain behavior of the system's output voltage using the ode45 solver under various external excitation frequencies and intensities. The results demonstrate that with appropriate adjustments to the mass of the tip magnet and the stiffness ratio of the dynamic amplifier, the proposed TPEH + DM system can harvest energy efficiently across a broad frequency range, even under low-orbit excitations. [ABSTRACT FROM AUTHOR]