Micropillared Surface to Enhance the Sensitivity of a Love-Wave Sensor
Résumé
Surface acoustic wave sensors have known outstanding development during the last decades. However, for biosensing applications, they struggle to compete with optical sensing technologies to reach the sensitivity of single molecule detection. In this work, we present a Love wave-based sensing platform that leverages the use of the local resonances of micropillars deposited on the surface of the guiding layer. We demonstrated numerically and experimentally that the Love wave interaction with the micropillars produces sharp attenuations dips in the transmission spectrum. These dips are associated with the excitations of flexural and torsional resonance modes of the pillars. We leveraged these modes to achieve high sensitivity detection of temperature variation, mass loading using sugar and micro-beads concentrations in aqueous solutions. Integrating a lattice of micropillars in SAW based devices offers real potential for extending the sensitivity space to detect low micro-particles concentrations.