Delimaras Vasileios (Phd Candidate)

Thesis title: Real Time Measurements of Oils Quality, based on the Changes in Electrical Characteristics
Supervisor: Spasos Michail
Advisory Committee Members:
Papakostas Dmitrios, Professor IHU
Hatzopoulos Argirios, Assistant Professor IHU

The scope of the PhD Thesis is to develop a novel method to measure capacitance, suitable for Interdigital Capacitance sensors (IDC). To begin with, an IDC sensor will be designed, that will be able to estimate the quality of an edible or lubricating oil or/and the degree of degradation, due to its continuous use in conditions that cause the degradation. The degradation of an oil is directly related to the changes in electric permittivity. As part of this research, the design of an IDC sensor will be implemented, so that changes in the electric permittivity of an oil are converted into changes in capacitance. Regarding the design of the sensor, the physical properties of the electrode material will be studied, as well as the substrate, the dimensions of the structure, the design geometry (parallel coplanar electrodes, fractal, or other more complex structure) and the degrees of freedom that may exist, in order to increase the sensitivity of the sensor. Furthermore, a novel capacitance measurement technique will be developed, using one-shot methods and capacitance multiplier techniques, to implement a Capacitance-to-Voltage converter (C-to-V Converter). The main goal of this thesis is for a device to be created, that will estimate the quality of an oil via the changes of its electrical properties in real time.