This award aims to build the fundamentals necessary to evaluate and maximize the transduction efficiency of vibratory energy harvesters that utilize liquid-state materials, namely ferrofluids, as the transduction element. To achieve this goal, a systematic three-level framework, which combines theories in fluid dynamics and electromagnetics with computational tools, is used to model and analyze the electro-magnetohydrodynamic behavior of liquid-state energy harvesters. At the first level, non-equilibrium molecular dynamics simulations are implemented to determine the relationship between the microscopic behavior of the ferrofluid nanoparticles and the associated bulk material properties of the fluid under non-equilibrium/dynamic conditions. At the second level, a reduced-order analytical model of the harvesting system is developed. The model, which invokes several justifiable assumptions on the dynamics, is used to provide a qualitative insight into the influence of the design parameters on the output power for simple device geometries. At the third level, a comprehensive computational model is developed and used to quantify the output power of the harvester for complex device geometries and at different scales.
If successful, the results of this award will lay the foundation and provide the necessary tools to build scalable, sensitive, and conformable energy harvesters with complex geometries and shapes, which, in turn, will open new, and, previously considered impractical avenues for vibratory energy harvesting. This will benefit many critical technologies including remote wireless sensors and implantable medical devices whose autonomous operation has been hindered by the lack of scalable and renewable power sources. Results from this research endeavor will bring us closer to the concept of "Autonomous Electronics" which will enhance the quality of life for patients with medical implants and will help avoid catastrophic failures of machines and structures similar to the infamous Saint-Anthony Falls bridge collapse.
