Acoustic levitation of a Mie sphere using a 2D transducer array

Most acoustic levitation techniques are limited to objects smaller than half the wavelength. To overcome this limit, different strategies have been proposed for suspending macroscopic in mid-air. Two approaches levitate spherical and non-spherical recently presented: acoustical virtual vortices boundary hologram method. However, former approach places high demands on available hardware due mandatory switching rate while latter uses a computationally expensive model that prevents future real-time manipulation. In present work, we demonstrate single-beam of Mie sphere using 2D transducer array. achieve this, employ fast sound field based harmonics expansion. obtain suitable array output, formulate an optimization problem maximizes stability keeping net force balanced. addition, prove local asymptotic equilibrium position determine domain attraction Lyapunov-based methods. experiments, show is stably levitated twin tuning forks trap, which results from superposition two trap signatures bottle signature. This result could open up possibility convenient non-contact manipulation by holographic elements applications.