A curvature self-detectable 3D arc-shaped IPMC/PVDF transducer with acoustic beam generation and tunable focal range abilities

The paper presents a novel 3-dimensional arc-shaped ionic polymer metal composite (IPMC)/PVDF transducer. It not only can generate focused acoustic beam and electrically manipulate the focal range of the acoustic beam but possesses curvature self-detectable function. This transducer involves three major components: 1) IPMC actuator with arc-shaped arm which allows a large curvature change motion under electrical actuation; 2) an ultrasonic PVDF film transducer attached to the front surface of the arm of IPMC actuator, which can manipulate the ultrasonic beam profile via the control of IPMC actuator. 3) A pair of interdigital transducers (IDTs) made on the PVDF film which is attached to the back surface of IPMC actuator. The IDTs function as a curvature sensor to detect the arm of IPMC actuator curvature change via the input and output voltage difference of the IDT pair. Detailed fabrication process and associated device characterization are described in the text. The developed IPMC/PVDF actuator successfully demonstrates the wide-ranging acoustic beam tenability of 100%.