The Defense Advanced Research Projects Agency (DARPA) awarded Mide a Phase I contract to develop a piezoelectric energy harvesting system (PEH) for a cubesat (U-class spacecraft) or similar small satellite while in an eclipse.
Significant stored energy is necessary to power satellite systems while the spacecraft is in the nighttime portion of its orbit. To enable the next generation of highly capable small satellites, battery energy density and solar cell efficiency must be complimented with other novel forms of energy harvesting. Piezoelectric energy harvesters convert the kinetic energy of structural vibration into useful electrical energy. Satellites do not have inherent structural vibrations; but a bistable perturbation mechanism with a thermally induced release of strain energy, can be used to excite a piezoelectric energy harvester. The Department of Defense has an acute need for such a system to efficiently trickle-charge a spacecraft’s batteries in periods of eclipse.
Mide is excited about the commercial opportunities this development effort and proposed technology offers. Vibration energy harvesting is currently limited to applications where the vibration environment remains at a relatively constant frequency. In practice though most vibration environments change and/or are made up of many different frequency components. There are also a lot of applications that contain much kinetic energy from shock events and other transient events; but this energy can’t be efficiently harnessed from traditional piezoelectric energy harvesting methods. Coupling a bistable perturbation mechanism with piezoelectric energy harvesting though can solve this problem and make piezoelectric energy harvesting viable for a wider range of applications.
Mide will be combining its expertise in piezoelectric energy harvesting and its commercial piezo product line with Professor Ryan Harne and his team at Ohio State's expertise in bistable systems for the project.