Mid-air acoustic tweezers for non-contact pick up using multi-channel controlled ultrasonic transducer arrays

Ultrasonic transducer arrays realize non-contact manipulation using acoustic radiation force. Non-contact pick-up conventionally uses hemispherical ultrasonic arrays. However, particles on reflective stages cannot be picked up. In this study, we propose a multi-channel hemispherical ultrasonic transducer array for non-contact pick-up on a rigid stage with reflection. The phase and amplitude of each channel are optimized using the sound reproduction method. This creates an acoustic trap at only the desired position, and pick up can thus be realized on the rigid stage. To the best of our knowledge, this is the first study to demonstrate non-contact pickup using this approach.