A Real-time Ultrasonic Manipulation System of Millimeter-Scale Particles

Non-contact particle manipulation can avoid damage, destruction, and contamination, thus playing a unique role in automated and intelligent production.Holographic acoustic tweezers based on transducers overcome the particle size limitations imposed by optical and magnetic tweezers, offering better compatibility.However, existing technologies based on standing waves have constraints on the spatial arrangement of transducers, which limits its application.In this paper, we propose a unilateral holographic acoustic tweezer system leveraging the twin trap, which achieves particle manipulation using a 88 transducer array and a controller implemented on an FPGA.We design an efficient transducer phase matrix generation algorithm and synchronize the driving signals through a shift register-based multiplexing circuit to eliminate phase errors caused by line delays.Real-time trajectory correction is achieved using two orthogonally placed cameras and a parallel target detection module on the FPGA.Experimental results demonstrate that our system can manipulate a polystyrene sphere with a diameter of 3mm along a 2cm square trajectory.Compared to existing technologies, our system shows significant improvement in manipulation speed and trajectory accuracy.