Bottle Trap Acoustic Transducer with PDMS Lens for Particle Trapping

Acoustic particle trapping is a promising technology due to its non-contact and non-invasive nature, which makes it safe for use in various applications such as noninvasive operation. One of the most effective and reliable methods of trapping particles is bottle-like trap. This trap utilizes a low-pressure zone surrounded by high-pressure acoustic waves to trap particles, which are then stabilized by the upward force from the bottom. However, current methods of generating bottle-like acoustic fields are expensive and has low fabrication precision, such as phase-controlled arrays or phase acoustic lenses. To address this issue, this paper proposes a new approach to design and fabricate a bottle beam acoustic transducer with binary acoustic lens. Our approach involves pasting a Polydimethylsiloxane (PDMS) film on a bulk Piezoelectric Transducer (PZT) to create an air cavity between them that can block parts of the acoustic wave to reconstruct bottle-like acoustic field. This transducer, which is fabricated using MEMS process, is highly precise, cost-effective, and compact compared to existing methods.