Design of Fresnel Lens-Type Multi-Trapping Acoustic Tweezers

Area of Science:

• Acoustic manipulation
• Biophysics
• Optical tweezers

Background:

• Traditional optical tweezers face limitations in manipulation scale and biological sample damage.
• Acoustic manipulation offers a non-invasive alternative for handling microscale objects.

Purpose of the Study:

• To propose and validate a novel acoustic tweezers system utilizing a Fresnel zone plate for beam forming.
• To demonstrate the capability of acoustic tweezers for precise particle manipulation and trapping.

Main Methods:

• Finite element analysis was employed to simulate acoustic intensity, pressure, potential energy, gradient force, and particle distribution.
• Acoustic tweezers were designed using a lead zirconate titanate (PZT) transducer (2.4 MHz, 100 V_peak-to-peak) in water.
• Fresnel lens design incorporated air reflection, acoustic impedance matching, and Fresnel half-wave band (FHWB) theory.

Main Results:

• The acoustic Fresnel lens successfully generated gradient force and acoustic potential wells.
• Simulations confirmed effective trapping of particles under 150 µm in diameter at minimum energy locations.
• The system exhibited good trapping ability for single particles and clusters.

Conclusions:

• The proposed acoustic tweezers with a Fresnel zone plate offer a viable method for manipulating microscale particles.
• This technology holds significant potential for applications in cell and microorganism manipulation.
• The study validates the effectiveness of acoustic tweezers for precise, non-invasive handling of biological samples.