Characterization of BiFeO3 thin film for tactile sensor using microcantilevers with piezoelectric capacitor and strain-gauge

Lead-free BiFeO₃ thin films for tactile sensor using microcantilevers have been prepared on Pt and SrRuO₃/Pt thin films on a SiO₂/Si substrate by RF sputtering, and the electrical characteristics have been optimized by controlling the substrate temperature, gas pressure, and oxygen partial pressure in deposition process. The BiFeO₃ thin film (thickness: 300 nm) deposited on SrRuO₃ (thickness: 80 nm) deposited at substrate temperature of 500°C in gas pressure of 0.6 Pa and oxygen partial pressure of 0.24 Pa has good crystallinity, ferroelectricity, and piezoelectric property. Therefore, it is demonstrated that BiFeO₃ thin film can be a good sensing material as a detection part of tactile sensor. Furthermore, a cantilever structure with piezoelectric capacitor and strain gauge has been fabricated and different time-dependent outputs from them can be obtained.