The acoustofluidic device consists of a microfluidic liquid channel and an air backing chamber that are in close proximity and separated by a thin silicon wall (fig. ). The thin wall can be excited by a piezoelectric transducer (piezo), which leads to bending of the wall in its eigenmodes. This design approach is advantageous as it allows us to shift the pressure node inside the liquid chamber towards the thin silicon wall and by that enables medium exchange through successful trapping of particles at the wall's displacement maximum.