High Performance Acoustofluidic Particle Focusing in Silicon-Based and Polymer-Based Devices Using Lateral Modes of Plate Transducers

We present the employment of lateral modes of piezoceramic plate transducers using the transverse piezoelectric effect for rapid acoustophoretic particle focusing in both silicon-based and polymer-based microfluidic chips. Based on the results of numeric simulations, we designed and fabricated high-performant silicon/glass chips capable of particle focusing in the experiment with an acoustic energy density Eac of more than 100 J m-3 at 22 Vpp and 544 kHz actuation. In a polymer-based device we observed particle focusing with Eac reaching about 15 J m-3 at 22 Vpp and 508 kHz actuation. Here, we are able to solve the paradox of particle focusing—which is assumed to require an anti-symmetrical pressure wave inside the channel—in a completely symmetric and symmetrically actuated system with the help of simulations. Although our models and investigations are similar to other work, e.g. [1-5], to the best of our knowledge, we are the first who explicitly employ lateral modes of piezoceramic plate transducers for acoustofluidic particle manipulation.