Ultrasonic Transducer encoding intersecting Bessel beams for particle patterning

Acoustic particle patterning has garnered significant attention within the realms of biotechnology and analytical chemistry due to its promising applications. This technique can be realized through the utilization of either surface acoustic waves (SAWs) or bulk acoustic waves (BAWs). While SAWs-based patterning boasts remarkable spatial resolution, it is confined to manipulation proximate to the surface of the solid transducer. In contrast, BAWs-based patterning permits intricate three-dimensional manipulation within substantial volumes of fluids. Notably, the realm of acoustic Bessel beams has also gained prominence in particle patterning. Nevertheless, the inherent properties of Bessel beams impose limitations on the achievable pattern shapes. This paper present a Micro-Electro-Mechanical Systems (MEMS) ultrasonic transducer founded on the principles of Bessel beams, facilitating precise particle patterning. By harnessing the capabilities afforded by MEMS fabrication techniques, this transducer affords on-chip integration, portability, heightened structural resolution, and augmented pattern area density.