Characterization of VO₂-Coated SiO₂ Micromechanical Bridges Heated by Light Radiation

This letter reports the resistivity variations for a VO₂ thin film on silicon dioxide (SiO₂) micromechanical bridges when the coating’s insulator-to-metal transition (IMT) is thermally induced by optical radiation with a 635 nm laser diode or by conduction using a heater. The coating’s resistivity and temperature coefficient of resistance (TCR) were calculated as a function of temperature through heating-cooling cycles. A resistivity change of nearly three orders of magnitude through the IMT was observed, and the results obtained for the two different heating methods were compared. A peak TCR of −85%/°C during the heating process and −80.8%/°C during cooling were measured.