A Miniature Energy Harvesting Device Using Martensite Variant Reorientation

Abstract

This paper presents a miniature energy harvesting device that makes use of stress-induced cyclic martensite variant reorientation in a Ni-Mn-Ga single crystal of 0.3x2x2 mm³ size. The stress- and magnetic field-induced reorientation is investigated for single crystalline Ni50.2Mn28.4Ga21.4 specimens of 0.3 mm thickness that are cut along the (100) direction and subjected to uniaxial compressive loading. A demonstrator is presented consisting of a FSMA specimen placed in the gap of a magnetic circuit to guide and enhance the field of biasing permanent magnets. The cyclic motion of a piezoelectric bimorph actuator is used to mechanically load the FSMA specimen. The corresponding change of magnetic flux induces an electrical voltage in a pick-up coil (N=2000 turns). The effects of biasing magnetic field, strain amplitude and strain velocity are investigated. An optimum magnetic field of 0.4 T exists, where the output voltage reaches 120 mV at a strain velocity of 0.006 ms-1.

Modeling and parametric studies of magnetic shape memory alloy–based energy harvester

“…One possible configuration of MSMA-based energy harvester is depicted in Figure 1, which has been taken into account by other researchers (Kohl et al, 2013; Niskanen and Laitinen, 2013; Saren et al, 2015; Suorsa et al, 2004). In this type of energy harvester, MSMA element is placed in between the air gap of a ferromagnetic core which conducts the magnetic flux.…”

“…In another configuration of energy harvesters, a ferromagnetic material is used to guide and enhance magnetic field generated by permanent magnet or electromagnet and MSMA sample placed between the air gap of this yoke. In previous modeling of this configuration, magnetic behavior of MSMA sample at different strains was approximated from the empirical magnetization curves (Kohl et al, 2013; Niskanen and Laitinen, 2013; Saren et al, 2015; Suorsa et al, 2004). Suorsa et al (2004) used an MSMA-based actuator system in the reverse operation as voltage generator.…”

“…Also, the variation of voltage or power versus time was not simulated. Kohl et al (2013) presented a miniature MSMA-based energy harvester with ferromagnetic core and investigated the effects of biasing magnetic field, strain amplitude, and strain rate on the induced voltage, but those related to coil parameters and electrical circuit were not studied. Approximating the dependence of MSMA magnetization on strain with a linear relation adds some errors to simulated results in comparison with experimental ones.…”

Analysis and modification of a common energy harvesting system using magnetic shape memory alloys

“…Modeling of the magnetic circuit can be easily carried out, and it has been performed in all works in a same way, yet different approaches have been considered in the alloy modeling. A purely empirical model is used in Kohl et al (2013), Saren et al (2015), and Suorsa et al (2004), in which the behavior of the alloy is predicted using easy-axis and hard-axis curves of MSMA material. In Bruno et al (2012), Sayyaadi and Farsangi (2015), and Sayyaadi et al (2018), thermodynamic-based models, which are on the basis of Kiefer model presented in several papers (Kiefer and Lagoudas, 2005, 2008a, 2008b) have been used.…”

The effect of magnetic field orientation on the open-circuit voltage of Ni–Mn–Ga based power harvesters

“…Schiepp et al 2012, Schluter et al 2012, Wegener et al 2014, however, such a low stress can be advantageous for power harvesting or sensing as it is easier to provide. Suorsa et al (2004), Karaman et al (2007), Bruno et al (2012), Kohl et al (2013) and Nelson et al (2014) demonstrated that high-frequency cyclic compressive, or impact loading, can induce power output with MSMAs. The power output is due to a deformation-induced change in magnetization, a.k.a.…”