Piezoelectric signals of HAp and collagen with different glucose concentrations: A method for diabetes detection

Piezoelectric signals were obtained from samples based on hydroxyapatite (HAp) and collagen (C) containing different glucose (G) concentrations. HAp was obtained by coprecipitation using Ca²⁺ and HPO₄^2- as precursor ions in solution. C and G were added at the beginning of the coprecipitation method during the HAp growth. The presence of glucose in HAp and collagen samples drastically reduces the voltage amplitudes and considerably increases the relaxation times of the piezoelectric signals. HAp and collagen are the main constituents of bone, muscle, etc., then, it is possible to use piezoelectric technology for local and early detection of high glucose concentrations: small pressures applied by electrodes or by actuators placed in appropriate places on the body to establish a background concentration and, from this, to determine regions of the body with high local glucose concentrations: weak signals and large relaxation times are associated with a diminishing in the sensitivity, and are indicative of the presence of regions of abnormally high glucose concentrations.