Femtogram mass sensing platform based on lateral extensional mode piezoelectric resonator

Abstract

This letter introduces a resonant mass sensor that is based on a lateral extensional mode piezoelectric resonator and has a minimum detectable mass of 10−15g at room temperature and atmospheric pressure. The resonator with size of about 200×50×1μm3 has a quality factor (Q) of >1400 at 60MHz, and as small as 0.1ppm shift of its resonant frequency can be detected. The 0.1ppm detection capability corresponds to a mass uncertainty of only about 4.6fg. We have experimentally demonstrated a minimum detectable frequency shift of ∼1.6ppm due to absorption of isopropanol vapor (73fg) on the sidewalls of the parylene-coated lateral extensional mode piezoelectric resonator.