Modeling Flutter-Based Microgenerators

Flutter-based micro generators have been successfully demonstrated to power wireless sensors. Since environmental wind speeds vary widely, flutter-based micro generators which are designed to operate within particular range of wind speeds will underperform elsewhere. At low wind speeds, magnets embedded near the ends of the belt will not move the desired distance between the coils, thereby reducing the energy conversion. A broadband flutter-based micro generator will have pick-up coils embedded on several vibrating elements with different dimensions. The coils are particularly concentrated near the point of maximum speed to maximize power output. The variation in fluttering element dimensions allows the microgenerator to generate considerable power at a wide range of wind speeds. In this work, we develop a mathematical model for the flutter-based micro generator, which addresses the wind – structure interaction, induced vibrations and electromagnetic transduction. The model primarily makes use of equations from bridge deck and thin plane analysis of flutter due to their similarities, and they are formulated to provide the velocity. This is later fed into electromagnetic transduction equations to calculate the output power. The model is useful to determine the significant design parameters of a flutter-based micro generator. The dynamic response and power output of a broadband micro generator with coils embedded on a set of cantilever films vibrating with respect to an external permanent magnetic field are calculated.