NSF Award
2414972
The Internet of Things (IoT) sensors-based monitoring enables data-driven decision-making in ‘smart’ Building/City/Factory/Agriculture/Healthcare settings, optimizing energy/resource utilization and minimizing the carbon footprint. One challenge with their wide adoption is limited battery life, requiring manual battery replacement, some of which could be in hazardous areas. This proposal aims to introduce and develop a fundamental realizable limit (FRL) power output vibration energy harvester to support milliwatts level of power requirement of IoT devices, offering a maintenance-free and green batteryless alternative, addressing the existing challenges, namely, (i) Narrow bandwidth operation, requiring harvester’s fine tuning per the source vibration, and (ii) Low energy conversion efficiency. The proposed harvester will offer a ‘plug & play’ universal solution for real-world vibration energy extraction at FRL, far surpassing the state-of-the-art energy efficiency. The developed technology will be for two different settings of harnessing machine versus structural vibrations for their remote monitoring, generating novel battery-free IoTs (for milliwatt level systems) with advanced application-specific integrated circuits (ASICs), contributing to ongoing national mission to strengthen semiconductor manufacturing and design ecosystem. The educational impact of the project will be through workforce training in cutting-edge areas of energy harvesting system and ASIC design, and STEM outreach activities at K-12 level.<br/><br/>The specific contributions of this proposed research are (i) Theorizing the Fundamental Realizable Limit (FRL) energy output as a function of vibration energy harvester parameters and input excitation characteristics; (ii) Developing mathematical approach to design a vibration energy harvester with self-tuned non-linear optimal displacement trajectory so as to attain FRL energy transduction irrespective of external excitation profile; (iii) Novel mathematical development of the interplay between the mechanical and electrical forces in a transducer for the co-design of an optimal electro-mechanical strategy for FRL operation and subsequent energy transfer to any desired electrical-load; (iv) A new Bayesian inferencing algorithm to realize ‘causal’ FRL operation for irregular vibrations having local extrema; v) Demonstrate FRL transduction strategy on piezoelectric-cantilever-based harvester by an integrated on-chip controller, with a novel switched energy extraction circuit to offer a dynamic optimal electrical loading to maximize transduction and fully transfer the transduced energy to the onboard storage; (vi) A mathematical framework to quantify the effect of various system design parameters on the energy conversion efficiency; (vii) Developing general design guidelines for harvester integrated IoTs by prototyping for self-powered machine- as well as structure-health monitoring applications.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
