Investigation of pyroelectric fields generated by lithium niobate crystals through integrated microheaters

• Published in: Sensors and actuators. A. Physical. Vol. 261; pp. 140 - 150
• Main Authors: Bhowmick, S., Iodice, M., Gioffrè, M., Breglio, G., Irace, A., Riccio, M., Romano, G., Grilli, S., Ferraro, P., Mecozzi, L., Coppola, S., Gennari, O., Rega, R., Coppola, G.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.07.2017; Elsevier BV
• Subjects: Crystals; Current impulses; Electric fields; Energy dissipation; Heat; Impulses; Joule effect; Lithium niobate; Lithium niobates; Power consumption; Pyroelectric fields; Pyroelectricity; Spatial distribution; Stability; Thermal effect analysis; Titanium; Pyroelectric fields; Lithium niobate; Thermal effect analysis; Joule effect
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2017.05.010

•We presented a deep investigation of the pyroelectric effect induced into ferroelectric LN by micro-heater structures integrated directly onto the surface of the crystals. Four configurations were considered in order to fully understand the distribution of the electric field under different stimulation conditions.•The effect of the micro-heater shape on the temperature distribution and consequently on the pyroelectric effect was evaluated using COMSOL™ Multiphysics. Simulations were validated by different experimental measurements.•In particular, the pyroelectric effect activated by the micro-heater was investigated analysing the current impulses detected using a micrometric metallic probe connected to an oscilloscope.•Finally, the high repeatability of the pyroelectric effect induced by the integrated micro-heater was demonstrated reporting the occurrence of the impulses.•The reported results let us to claim that by regulating the rate of heating or cooling of the different design of micro-heaters, the occurrence of the pyroelectric effect from the –Z surface of the LiNbO3 can be manipulated and/or controlled is an easy and efficient manner compared with traditional ways of thermalizing the crystal. We present a deep investigation of pyroelectric fields generated by lithium niobate crystals through integrated microheater structures. The microheaters are made of highly compact titanium microcircuits able to dissipate heat through a low-power consuming Joule effect. Microheaters with diverse geometries were designed and fabricated on the +Z face of lithium niobate crystals, in order to characterize pyroelectric fields with different distributions. The pyroelectric effect was studied under ambient conditions analysing the current impulses detected using a metallic probe connected to an oscilloscope. The current impulses were related to the air breakdown induced by the electric field arising between the −Z face of the crystal and the metallic tip. We show that the fabrication technique is relatively easy to accomplish and we analyse the thermal behaviour of the microheaters both theoretically and experimentally. The results show how such microheaters are able to control the intensity and the spatial distribution of the pyroelectric fields at microscale.