Utilizing Lateral Plate Transducer Modes for High Quality Acoustofluidics in Silicon-Based Chips

By establishing and exploring a numeric model of an acoustofluidic device driven by a piezoelectric plate transducer, we discovered simple and distinct vibrational patterns with high displacement amplitudes for a lateral vibrational mode of the transducer plate. With the design based on a numerically optimized chip-geometry for this particular lateral mode, we fabricated high-performant chips enabling rapid and accurate particle focusing, where the acoustic energy density is exceeding 100 J/m
³
at actuation frequencies around 540 kHz, while heat generation remains low. We excite higher order harmonics leading to multiple separate lines of particles along the channel. With the custom-made chip holder featuring integrated fluid connections and transducer support, we are moreover able to swiftly mount microfluidic chips directly after dicing without any further preparation.