Parameters determination (energy, charge, electric field, shape) of output profiles of HAp-collagen-glucose-based double layer capacitors; possibility for diabetes detection

Abstract

Numerical values of important parameters associated with a piezoelectric material containing an electrolyte and subjected to external stress were obtained; the applied stress produced, almost instantly, induced charges on the material's surface; these charges move the ions of the electrolyte toward the charged surfaces forming the electric double layer EDL; these two charged surfaces give place to the formation, in the interior of the material, of a particular type of capacitor called double layer capacitor DLC. The values of these parameters associated with DLC show interesting and important characteristics: DLC can store considerable amounts of energy and electric charge, as well as high electric fields; these characteristics can explain the extreme sensitivity of the human body to sense extraordinarily small mechanical actions. While the time to induce the charge on the surface τ_e is instantaneous, the time τ_i to form EDL is not; this time controls the shape of the output voltage signals. The presence of glucose modifies the piezoelectric signals allowing to use these profiles to diagnose diabetes. Additionally, expressions were obtained for the chemical capacitance C_μ as a function of voltage and glucose concentration.