Figure 3. Acoustophoretic handling of heavy matter in air.

(a) The acoustophoretic set-up and its function. The emitters are Langevin piezo transducers (LPTs) used as acoustic sources. The driving voltage is varied within time t between two adjacent LPT (A₁ and A₂) with a maximum value of A₀ (120 Volts). This modulation allows the smooth motion of the acoustic node during a period T, time needed to move the acoustic node between two adjacent emitters. (b) Contactless transport of a steel ball. The sphere size is 5 mm in diameter and travels between two neighboring emitters. The dimple on the morphing reflector travels along with the acoustic field and the sample. For this experiment, a PDMS membrane was used.