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/m3 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 custommade 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.