This award supports fundamental research into the mechanisms facilitating power harvesting with magnetic shape memory alloys and the development of tools to accurately predict output power during various load conditions. Power can be generated from environmental sources like wind, waves, or structural vibrations using various technologies. Recently, it has been shown that useful electrical power can be harvested from the environment using a relatively new type of material - magnetic shape memory alloys. While this capability of the material has been demonstrated experimentally, the mechanisms responsible for it are not well understood. Consequently, current mathematical models of this material fail to predict power output accurately, hampering the development and optimization of magnetic shape memory alloy based power harvesters. Successful completion of this work will significantly deepen understanding of this new material and could lead to new technologies to power, or power assist, sensors deployable in remote locations (e.g. to monitor forest conditions) or in infrastructure (e.g. to monitor operational safety).
The main objectives of this project are to understand the underlying microstructural mechanisms occurring in magnetic shape memory alloys during power harvesting and to mathematically embed these mechanisms into a material constitutive model that accurately predicts change in magnetization, power output, and strain. In order to understand the mechanisms that lead to power harvesting with these materials, microscopic observations will be performed simultaneously with macroscopic magneto-mechanical characterization; this will allow for the two scales to be correlated. Observations about changes in the microstructure, during various loadings, will be incorporated into a thermodynamics based constitutive model of the material. The model will be validated against macroscopic magnetization, magnetic field, strain, stress, and power data obtained experimentally, under a wide variety of magneto-mechanical loading conditions. Understanding of the underlying mechanisms causing power harvesting, including the magneto-mechanical interdependencies, and embedding these mechanisms into a constitutive model will be a major advance in the field and will yield knowledge that can be employed to develop new technologies with this material and may be extended to understand and model other adaptive or magnetically active materials.