Aluminium nitride piezoacoustic transducer design for CMOS compatible high-performance ultrasound devices

Abstract

Piezoelectric materials are fundamental to ultrasound probes and scanning devices, enabling the bidirectional conversion of mechanical energy into electrical signals for applications in medical imaging, fingerprint recognition, and non-destructive testing. This capability supports accurate visualization of internal structures, thereby enhancing diagnostic precision. Traditionally, lead zirconate titanate (PZT-4) has been the dominant choice for handheld ultrasound probes due to its high piezoelectric coefficients; however, its limitations include low output efficiency, brittleness, high temperature processing requirements, and significant environmental hazards, particularly marine eco-toxicity during disposal. To overcome these drawbacks, this study investigates aluminium nitride (AlN) as a safer, environmentally sustainable, and thermally stable alternative. AlN offers compatibility with complementary metal oxide semiconductor (CMOS) technology, facilitating integration into compact, high-performance ultrasound devices suitable for biomedical and portable applications. Using COMSOL Multiphysics simulations at 200 kHz, the piezoacoustic response of AlN is analyzed to evaluate its acoustic field behavior under specific electrical inputs. Results highlight AlN’s ability to generate uniform acoustic pressure distributions, supporting its potential for photoacoustic imaging and advanced biomedical diagnostics. This work establishes AlN as a promising material for next-generation ultrasound transducers, combining environmental safety with superior functional performance.