A Thermomagnetic Energy Harvester - CERES PROJECT

The present Master Thesis work is a dissertation on the prototyping of the first colloidal thermomagnetic energy harvester. The research programme (CERES Project) has been conducted within the Center for Sustainable Future Technologies (CSFT) at Istituto Italiano di Tecnologia (IIT) of Turin. The three main phases reported here are: first, a description of the context and the physical background of this device, then, the experimental setup of the prototype, and finally, the analysis of the data collected as the output of the harvester. Moreover, a new matrix representation of the physical quantities involved is presented. The CERES paradigm exploits the incredible thermomagnetic properties of ferrofluids, a suspension of magnetic nanoparticles (NPs) dispersed in a fluid solvent. Since their magnetization is thermal dependent, the interaction between a magnetic field and thermal gradients produces cycling magnetic forces, convertible into electric energy. The first phase mainly dealt with the setup of a lab-scale first prototype of the CERES reactor, with a toroidal geometry. In particular, the main electronics to power up the system has been built, starting from a power supply chain composed of 8 suppliers. These ones were connected to two consecutive stages of 32 voltage regulators each: the first ones reduced the output voltage of the supplier from 12V to 5V, while the second linear regulators lowered again the tension, reaching an output of 2:3V. In this way, it was possible to switch on all the 32 Peltier cells, responsible for the production of a thermal gradient among the inner and outer walls of the reactor. For what concern the magnetic field, it was originated by more than 50 permanent magnets, placed near the Peltier cells of both inner and outer walls. The second phase involved the implementation of a large number of temperature sensors around the entire system. In details, 32 thermocouples were used to monitor and measure the temperature of the ferrofluid, and 16 thermistors, one for each Peltier cell station. Furthermore, all these devices were connected to a DAQ system from National Instruments ® , coupled with a LabView software. Then, in order to collect the output electrical energy, the entire toroidal structure has been wrapped-up with a large number of coils, transforming the reactor in a sort of giant solenoid, able to exploit the magnetic field originated by the moving NPs.