Laser induced ultrasonic transducer and its application in Magneto-acousto-electrical tomography

Various types of ultrasound transducers have been developed and widely used in biomedical science and industrial testing applications. However, conventional ultrasound transducer is incapable for broad bandwidth ultrasound which provides high spatial resolution imaging. In addition, conventional ultrasound transducers are PZT transducers, which means that these transducers suffer from electromagnetic interference (EMI) in electronically harsh environments. In this study, a Laser induced ultrasonic transducer (LIUT) based on optoacoustic effect is proposed to demonstrate its capability for medical imaging of a gel phantoms. First, the multi-physical field coupling method of electromagnetic-solid-ultrasonic field is deduced, and the ultrasonic field characteristic of LIUT is simulated. And then the LIUT was fabrication by coating the carbon black(CB)-polydimethylsiloxane (PDMS) based polymer composite on the substrate. The characteristics of sound field are verified by experiment and simulation. The amplitude and -6 dB frequency bandwidth of the generated ultrasound were measured to be 2.5MPa and 8MHz, respectively. Finaly, the presented LIUT was applied for magneto-acousto-electrical tomography (MAET) based on ultrasound excitation.