• Ultrasonic and electrical impedance multi-sensing method for biological tissue based on low-acoustic-impedance 1–3 piezoelectric composites was evaluated. • The 18.4% volume fraction composite exhibited higher ultrasonic reflection amplitude and significantly shorter wave width. • It was presented that electrical impedance measurement using surface electrodes of piezoelectric composites was valid for multi-sensing method. This paper proposes a multi-sensing device based on piezoelectric composites that enables simultaneous ultrasonic and electrical impedance measurements of biological tissue. The proposed device measures the ultrasonic property of the biological tissue by directly applying piezoelectric composites, which have low acoustic impedance – a key advantage of piezoelectric composites. Electrical properties are also measured using surface electrodes of piezoelectric composites although it is difficult to measure them by the ultrasonic devices since they typically have acoustic matching layers to reduce high acoustic impedance. In the experiment, ultrasonic and electrical measurements in saline solution are demonstrated using three types of 1–3 piezoelectric composites with different resin-to-ceramic ratio and piezoelectric ceramic. The results show that both properties can be measured using 1–3 composites, and the 18.4 % ceramic volume fraction provided the best overall performance among the tested composites.
Kimoto et al. (Sat,) studied this question.