Miniaturized acoustic suction tweezers: Lift control and cap design for mobile applications

We propose a compact and mobile acoustic suction tweezer system capable of lifting small objects using acoustic radiation force. The device integrates a single ultrasonic transducer with a specially designed acoustic focusing cap, allowing for manipulation of objects in mid-air. Unlike conventional acoustic tweezers that rely on large transducer arrays and complex phase control, our approach emphasizes extreme miniaturization, low power consumption, and structural simplicity, enabling battery-powered and mobile applications. Multiple cap geometries were fabricated via 3-D printing to explore the influence of acoustic cap design on lift characteristics and object capture efficiency. Experimental results demonstrate that the system can reliably lift and release various small objects regardless of the surface material, shape, or size, indicating robust and versatile suction behavior. The ability to manipulate objects with diverse geometries—including irregular and asymmetric forms—highlights the adaptability of the system to real-world scenarios. Notably, the lift force is achieved even when the object size exceeds the acoustic wavelength, suggesting that cap geometry plays a critical role in shaping the acoustic field and enhancing radiation force. This study provides insight into the role of cap design in acoustic manipulation systems and presents a promising approach for miniaturized, field-deployable levitation tools.