Investigations on the existence of piezoelectric property of a bio-polymer – chitosan and its application in vibration sensors

Abstract

A variety of physical and chemical properties of bio-polymers like chitosan have been investigated although their inherent behavior, such as piezoelectricity, has not been investigated to date. In this study, an attempt has been made to investigate the presence of non-centrosymmetry in chitosan through X-ray diffraction (XRD) analysis and second harmonic generation (SHG) experiment. Existence of piezoelectricity is established by determining d₃₃ coefficient for various pressures. With the help of the above mentioned results, a new application of the bio-polymer chitosan as a piezoelectric element in vibration sensors has been analyzed. To fabricate vibration sensor elements, chitosan was dissolved in various organic acids and its suitability for these applications was studied. Through isolation resistance measurement, the fabricated sensor is found to exhibit very high isolation, which is suitable even in hazardous environments. All the abovementioned investigations reveal the suitability of using chitosan in vibration sensors.