Theoretical and experimental investigation of a quad-stable piezoelectric energy harvester using a locally demagnetized multi-pole magnet

Su, Xukun; Leng, Yonggang; Sun, Shuailing; Chen, Xiaoyu; Xu, Junjie

doi:10.1016/j.enconman.2022.116291

Cited by 20 publications

(6 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, when then excitation is dropped to 0.2 g, only those energy harvesters with shallow potential wells can perform inter-well motion and produce massive power. The variation of the potential function with respect to the rotation angle φ of LDPM C1 is very similar to traditional energy harvesters with a normal magnet, but varying the separation distance, for example, see [52] for example. The theoretical results and experiments demonstrate that this method with LDPM does not change the overall size and shape, hence it can serve as a promising alternative approach.…”

Section: Parametric Studymentioning

confidence: 75%

“…The magnetic field of ferromagnetic materials can be obtained once the magnetization distribution of the ferromagnetic object is known [51]. Since that in this study, the distance between the tip magnet and the LDPM is sufficiently large, the magnetization of the LDPMs can be assumed to be piece-wise uniform, hence the magnetic field outside the magnet can be calculated via the magnetizing current method [41,52].…”

Section: Magnetic Field and Magnetic Forcementioning

confidence: 99%

“…Based on the magnetizing current method [52,54], the LDPM can be represented by multiple magnetizing current distributions, appearing at each boundary of the LDPM, as shown in figure 4. The magnetizing current distribution along each boundary is [41,55]:…”

Section: Magnetic Field and Magnetic Forcementioning

confidence: 99%

“…Let the normal vector of the moving trajectory of the tip magnet be n t and the rotation angle be θ, as shown in the diagram in figure 2. They can be approximately expressed as [52]:…”

Section: Magnetic Field and Magnetic Forcementioning

confidence: 99%

“…where M t is the magnetization of the tip magnet, S i , i = 1 − 4 are the surface boundaries of the tip magnet, details of the derivation can be found in [52,56]. Since the work done by the magnetic force is:…”

Section: Magnetic Field and Magnetic Forcementioning

confidence: 99%

See 4 more Smart Citations

A mechanical-free designing method for tailoring nonlinearity in bi-stable piezoelectric energy harvesters

Leng

et al. 2023

Smart Mater. Struct.

Self Cite

View full text Add to dashboard Cite

This paper presents a mechanical-free method for providing and tailoring the nonlinear force in bistable piezoelectric energy harvesters (BPEHs). The nonlinear force can be tailored to obtain a lower threshold for inter-well motions, or for the harvester to operate at various excitation levels and frequencies without changing the mechanical structure or the overall assembly. In BPEHs, the nonlinear force is tailored to match a specific excitation level and frequency, and the mechanical structure is designed to achieve higher strain (and thus higher output power). The design of nonlinearity can be separated from the design of the mechanical structure by using magnetic interactions. Hence, the design of nonlinearity is the arrangement of the external magnetic field of the harvester. In this paper, arranging the external magnetic field is achieved by arranging the magnetization distribution of one external magnet. With the locally demagnetizing technique, a uniformly magnetized permanent magnet can be locally demagnetized with desired patterns. The external magnetic field is provided by a locally demagnetized permanent magnet (LDPM). The nonlinear force can be tailored by simply altering the properties of the LDPM. This method converts the design of providing and tailoring the nonlinear force into the design of the LDPMs. For demonstration, we show that without increasing the distance between magnets, the potential barrier of the bistable system is dramatically reduced by using LDPMs. Melnikov’s method is utilized to show that the energy harvesters with LDPMs possess a lower threshold for homoclinic tangency than energy harvesters with a normal magnet. The influence of the parameters of the LDPMs on the energy harvesting performance is studied via simulations and experiments. Results show that without violating the mechanical part, changing the locally demagnetizing patterns can effectively change the harvester's working frequency and excitation threshold.

show abstract

Section: Parametric Studymentioning

confidence: 75%

Section: Magnetic Field and Magnetic Forcementioning

confidence: 99%

Section: Magnetic Field and Magnetic Forcementioning

confidence: 99%

“…Let the normal vector of the moving trajectory of the tip magnet be n t and the rotation angle be θ, as shown in the diagram in figure 2. They can be approximately expressed as [52]:…”

Section: Magnetic Field and Magnetic Forcementioning

confidence: 99%

Section: Magnetic Field and Magnetic Forcementioning

confidence: 99%

See 3 more Smart Citations