Self-exciting, self-sensing PbZr 0.53Ti 0.47O 3/SiO 2 piezoelectric microcantilevers with femtogram/ Hertz sensitivity

Abstract

Piezoelectric microcantilever sensors (PEMSs) consisting of a piezoelectric layer bonded to a nonpiezoelectric layer offer the advantages of electrical self-actuation and self-detection. Here we report PEMSs 60-300 μm. in length fabricated from 1.5-μm-thick sol-gel PbZr 0.53Ti 0.47O 3 (PZT) films with a 2 μm. grain size, a dielectric constant of 1600, and a saturation polarization of 55±5 μC/cm 2. The PEMSs exhibited up to four resonance peaks with quality factors Q ranging from 120 to 320. In humidity sensing tests, a PEMS with a 60×25 μm PZT/SiO 2 section and a 24×20 μm SiO 2 extension exhibited 1 × 10 -15 g/Hz mass sensitivity, two orders of magnitude better than the sensitivity of the current PZT PEMS. © 2006 American Institute of Physics.