Optimized MEMS Circular Membrane Resonators for Mechanical Energy Harvesting and Sensing for IoT Application

The Internet of Things (IoT) definition tends to be the common denominator of all distributed sensing systems, providing intelligent entities with connectivity and interoperability within a pervasive network. Normally, IoT nodes are powered with the conventional batteries, but since the lifetime of battery is constrained and often their replacement is impracticable. Thus, there is strong need of self-powered devices or alternative sources of energy to continuously power the IoT devices. Proposed solution to this limitation is use of vibration based Micro electromechanical systems (MEMS) piezoelectric energy harvester that could provide a free, green, and virtually unlimited secondary powering source over traditional energy sources (batteries). Due recent development in field of MEMS technology, vibration energy harvesting is gaining attention and with an abundant vibration energy available generate power using MEMS devices within microwatts to few mW ranges, it is going to become the technology of future. In this paper we are proposing variants of circular membrane type of MEMS structures which can be used for piezoelectric vibrational energy harvesting and sensing. The aim of proposed structures is efficient energy harvesting as well as condition monitoring of remote or standalone vibrating sources such as water pumps and rotors that produce a narrow frequency range vibration depending upon the physical condition of the source.