Energy Harvesting from the Human Body for Portable Biosensors and Implantable Biomedical Devices

Sobianin, Ihor (2024). Energy Harvesting from the Human Body for Portable Biosensors and Implantable Biomedical Devices. PhD thesis The Open University.

DOI: https://doi.org/10.21954/ou.ro.00100260

Abstract

Wearable biosensors and implantable biomedical devices frequently rely on battery-stored energy, whose replacement might be associated with pain, surgeries and data acquisition discontinuity. Energy harvesting is one way of tackling those issues. The cardiovascular system represents a reliable source of periodic vibrations suitable for harvesting. This thesis investigates energy harvesting from radial artery pulsations.
The harvester concept features hybridisation of a piezoelectric nanogenerator (PENG) and the reverse electrowetting on dielectric phenomenon (REWOD). Synthesis of the theoretical hybrid energy harvester within COMSOL Multiphysics was carried out. The investigation of influence of the PENG material, its thickness, harvester diameter and actuation signal frequency was carried out. An experimental setup with a corresponding computational model were designed. The setup featured a non-contact method of the harvester excitation and automated data acquisition system. The influence of various geometrical parameters on power output was reported. The simulation results captured the empirical data main trends. A 3D-printed energy harvesting platform was developed. A pulse waveform was simulated based on the electro–hydraulic analogy Windkessel model of the human cardiovascular system. A 3D printed platform prototype was manufactured, and physiological data regarding the influence of the elastic film thickness, the platform fit and wrist position was acquired. The main finding was that a significant amount of radial artery energy was distributed across harmonics of the heart rate fundamental frequency. A REWOD configuration was derived from the experimental setup. The influence of displacement amplitude, initial distance between the electrodes, the droplet volume and electrolyte concentration were studied. Flexible thin PVDF films with varying percentage of ZnO filler were manufactured using spincoating and were subsequently characterised chemically, morphologically and electrically.
The thesis shows promising results in using radial artery energy harvesting for biomedical devices, formulates an innovative hybrid energy harvester concept and opens new venues for future work in the area.