Noncontact Dynamic Oscillations of Acoustically Levitated Particles by Parametric Excitation

A graduate laboratory experiment to study the dynamics of an acoustically levitated particle

“…To estimate the forces, we measured the static displacement (r s , z s ) of Styrofoam particles with known radii and density (31 kg m −3 ) for different voltage values, where the potential is proportional to the input voltage squared, V 2 [4]. From equation (9), the particle should satisfy the following equations…”

“…These forces can be harnessed to design an AL end-effector, a device capable of manipulating small rigid particles without contact. The setup was designed to demonstrate the intricate nonlinear dynamics of an acoustically levitated spherical particle while avoiding advanced nonlinear dynamic phenomena such as parametric resonance [4,34] and acoustic streaming [17]. Moreover, it was designed to be interactive and relatively slow so that the phenomena can be observed without unique measuring equipment.…”

“…Standing wave acoustic levitation is achieved by nonlinear acoustic radiation forces that counteract gravity and trap objects steadily in fluids [2][3][4][5][6]. These forces emerge due to acoustic radiation pressure, which is the pressure impinging upon objects in an acoustic field.…”

“…Indeed, due to nonlinear phenomena, the harmonic waves are not pure sinusoids [1,7]. As a result, the time-averaged acoustic pressure does not cancel out, and the resulting forces acting on small particles can be used to trap them in mid-air [4][5][6]8]. The associated nonlinear phenomena are often negligible, but they are significant at high frequencies and high pressure.…”

Coupled oscillation and spinning of photothermal particles in Marangoni optical traps

“…However, in most synthetic systems that rely on complex chemical or biochemical reactions, the nature of interactions between different elements is typically hardwired with limited ability to dynamically adjust coupling parameters. Similar limitations on geometric reconfigurability and tunability of coupling are found in physical particle oscillator networks, such as in acoustically levitated oscillators (14). In contrast, the effectiveness of natural control systems stems from oscillatory elements that can reconfigure their interactions rapidly, as observed in transitions of insect flight modes or animal gait patterns (2,15).…”