An electro-mechanical dynamic model for flexoelectric energy harvesters

Abstract

Flexoelectricity is a universal electro-mechanical coupling effect that occurs in dielectrics of all symmetric groups and becomes dominant at the micro- and nano-scales. It plays an important role in evaluating micro-electro-mechanical systems (MEMS) such as energy harvesters which convert vibrational energy to electric energy. At finer length scales, micro-inertia effects significantly contribute to the behavior of flexoelectric materials due to the mechanical dispersion. Hence, to properly characterize the vibrational behavior of MEMS, a reliable theoretical approach is required accounting for all possible phenomena that affect the output of the system such as voltage or power density. In this work, we present a consistent (dynamic) model and associated computational framework for flexoelectric structures to study the characteristics of the vibrational behavior of energy harvesters showing the dominance of the flexoelectric effect at micro- and nano-scales. In this context, we quantify the impact of the micro-inertia length scale and the flexoelectric dynamic parameter on both frequency and time responses of energy harvesters.

Nonlinear analysis of flexoelectric acoustic energy harvesters with Helmholtz resonator

“…By substituting Eqs. ( 21) and ( 22) into it and neglecting the inertia and voltage terms, the relationship can be expressed as (24) where…”

“…Concerning the energy conversion mode, AEH can be classified as electrostatic [17], electromagnetic [18], piezoelectric [1], [5]- [7], [12], [19], and flexoelectric types [20]- [24]. For example, a model was proposed in which a Helmholtz resonator's bottom cavity plate is replaced by a flexible piezoelectric film in the work of Horowitz [8].…”

“…Wang and Wang [25] introduced an analytical model for nanoscale flexoelectric energy harvesters that comprises a cantilevered beam, a proof mass, and a flexoelectric layer. Thai [24] presented a consistent model and associated computational framework for flexoelectric structures to study the characteristics of the vibrational behavior. Among them, the Helmholtz resonator has advantages such as simple structure, strong sound absorption ability, high sound pressure amplification coefficient, and high energy conversion rate.…”

Recycling and Upcycling in the Electro-Mechanical Domain: A Review of Current Practices

“…This approach represents a significant advancement in upcycling, as it allows for the creation of efficient and low-power digital circuits, which are crucial for sustainable electromechanical system design. Thai et al (2023) explore an electro-mechanical dynamic model for flexoelectric energy harvesters, an important aspect of upcycling in electro-mechanical systems. Flexoelectricity, a universal electro-mechanical coupling effect dominant at micro-and nano-scales, plays a vital role in evaluating MEMS such as energy harvesters that convert vibrational energy to electric energy.…”

Nonlocal strain gradient‐based nonlinear dynamics of sinusoidal impulsive actuated porous/piezoelectric multilayer energy nanoharvesters

“…Xie et al 49 and Fattahi et al 50 predicted the size‐dependent nonlinear secondary resonance of hard excited FG porous beams at microscale and nanoscale. Thai et al 51 investigated the influences of nonlocal gradient and dynamic flexoelectric effects on the behaviors of flexoelectric micro energy harvesters and their performance under various loading conditions. Sahmani et al 52 anticipated the small scale‐dependent nonlinar primary resonaane of FG porous nanoshells in the presence of modal interaction.…”