Générateur MEMS bistable : solution pour l'alimentation des capteurs pour des bâtiments intelligents

Improving energy efficiency of buildings is of critical importance to reduce power consumption in both private and public building sectors. Various autonomous sensors are used to monitor relevant figures(temperature, pressure, light, smoke detection) to optimize the energy fluxes and reduce the global powerconsumption. They are however powered by batteries. Though, ambient vibrations can be found in critical placessuch as HVAC (Heating, Ventilation and Air-Conditioning) ducts. These are deemed to be a favorable technical and industrial context to develop relatively universal vibration energy harvesters to be used for intelligent buildings in order to supply distributed control system. The potential high volume of autonomous sensors to be powered and low power consumption (ultra-low power electronics and moderate transmission duty cycles) justify the choice of a MEMS scale approach. The SYMME lab proposed a monolithic bistable energy harvester whose performances overcome the state of the arts' (0.45 mW/cm3, from 20 to 66 Hz at 0.6g). Based on this work, a first MEMS BO prototype has been designed and realized through a joint collaboration between Univ. Savoie Mont Blanc and Univ. Hyogo. The macroscale bistable harvester makes use of piezoelectric transduction to generate theelectrical energy while the MEMS devices, at this stage, demonstrated the expected mechanical behavior. Combining the expertise of the SYMME Lab on macro-scale bistable generators and the MEMS know-how of the Maenaka lab, the project will focus on the realization of nonlinear MEMS generator exhibiting large operation bandwidth (10Hz – 100Hz) at low acceleration (around 1 m/s2).