Integration of Localized Surface Plasmon Resonance (LSPR) Sensor on SAW Device - Influence of Longitudinal Wave Radiated Into Liquid by SAW on LSPR sensor-

When a liquid is placed on the surface acoustic wave propagation surface, longitudinal waves are radiated into the liquid. The acoustic radiation force of the longitudinal waves can transport droplets. A localized surface plasmon resonance sensor (LSPR) with gold nanoparticles on the surface of the SAW device was fabricated for droplet measurement. The LSPR sensor is affected by cavitation bubbles generated by acoustic streaming. In this paper, a method to avoid cavitation bubbles is investigated. As a result, it was clarified that the bubbles do not occur when the liquid temperature is kept at 40 °C. The dependence of the velocity of acoustic streaming on the input voltage was also investigated using a water tank.