Particle collection using a Lamb wave device with a non-piezoelectric glass substrate

Abstract

An acoustic Lamb wave device using a non-piezoelectric substrate is reported for particle collection. The traditional high-precision interdigital transducer (IDT) is replaced by a common piezoelectric transducer (PZT), and the traditional LiNb O 3 piezoelectric substrate is replaced by a non-piezoelectric glass. The Lamb wave is excited by the vibration of PZT and propagates along the substrate, interacting with the droplet on the substrate. A single asymmetric acoustic streaming vortex is generated in the droplet by irregular design of the glass substrate to drive the droplet movement and provide the collection of particles scattered on the substrate. The flow inside the droplet under acoustic streaming and applied forces of the particles, as well as the motion characters of the particles, were investigated. The key factors on collection efficiency and collection rate of particles were characterized by experiments. Compared with traditional surface acoustic wave (SAW) devices, the distinct advantages of the proposed device are simplicity in manufacturing, low cost and easy operation. The excited Lamb wave also has the features of low frequency, low energy attenuation and long transmission distance. The particle collection based on the Lamb wave device shows good controllability and high collection efficiency. In addition to particle collection, other applications based on the Lamb wave device are suggested for future investigation, such as microchannel self-cleaning and oil-water separation.