Integrated hybrid micro energy harvester based on thermal and vibration using op-amp for biomedical devices

Abstract

Background: Energy harvesting is the process of capturing tiny amounts of energy from one or more innate energy sources, accumulating the collected energy and storing it for future use. Batteries are not really practical because the lifetime of a battery is limited, its replacement and recharging could become major bottlenecks. Therefore, energy harvesting is playing a more and more vital role in the supply of energy to real life applications, such as wireless sensor networks and health care monitoring. Materials and Methods: This study presents the design of ultra-low-power hybrid micro-energy harvester (HMEH) circuit with hybrid inputs of thermal and vibration. The main purpose of the hybrid inputs in the system is to support the low input, especially of thermal energy, thereby ensuring that energy continuously flows. Both inputs are simultaneously present and will be combined in parallel at 0.02 and 0.5 V for thermal and vibration inputs, respectively under frequency of 10 Hz. When only thermal energy exists, the system is considered to have the minimum condition, the maximum condition refers to when both inputs exist. Results: This HMEH system abled to achieve the output of 4.0 and 3.94 V for simulation and hardware respectively using 1 megaohm (MS) load resistance. From the simulation and experimental work, the generated output power of the system is 1.6 and 1.182 mW. Conclusion: The proposed HMEH system achieves better performance and functionality when work under the maximum condition. The performance of the HMEH system is compared between the simulation and hardware implementation.