Optimisation of an acoustic resonator for particle manipulation in air

An acoustic resonator system has been investigated for the manipulation and entrapment of micron-sized particles in air. Careful consideration of the effect of the thickness and properties of the materials used in the design of the resonator was needed to ensure an optimised resonator. This was achieved using both analytical and finite-element modelling, as well as predictions of acoustic attenuation in air as a function of frequency over the 0.8 to 2.0 MHz frequency range. This resulted in a prediction of the likely operational frequency range to obtain particle manipulation. Experimental results are presented to demonstrate good capture of particles as small as 15µm in diameter.