Miniaturized focused ultrasound transducer based on a 3D-printed phase-reversal Fresnel acoustic lens

To address the issues of large size, complex manufacturing processes, and limited phase control accuracy in traditional Fresnel lenses, this study proposes a miniaturized focused ultrasound transducer (MFUT) based on Three-Dimensional (3D) printing technology, which integrates a phase-reversal Fresnel lens structure and a dual-layer matching layer design. Its ultra-compact dimensions (1.5 mm in thickness, 6 mm in diameter) and lightweight characteristic (weight 0.14 g) result in a volume approximately 75% smaller than that of conventional transducers. Experimental results show that the transducer achieves an acoustic pressure gain of 130% at a focal distance of 4 mm, with a full width at half maximum (FWHM) of 0.45 mm. This customizable and highly efficient design demonstrates significant potential for acoustic field manipulation in applications such as transcranial ultrasound therapy.