Highly Sensitive and Stretchable Ultrasonic Transducer Array for Object Internal Characteristics Detection in Robotics

Abstract

This paper presents a novel stretchable ultrasonic transducer array with high-pressure resistance and sensitivity for the integration of robotic arm to detect internal characteristics under complex shaped surfaces. The proposed transducer array has a 3×3 array of 1-3 composites that using bidirectional stretchable electrodes to enhance its stretchability and a pressure block to improve resistant force. Exploiting the Ag nanoflakes as the material of electrodes improves the interfacial bonding with polymer substrate. A low-cost fabrication method is developed to fabricate the ultrasonic transducer array. Experimental tests showed that the fabricated ultrasonic transducer array has good electromechanical coupling ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">eff</sub> = 0.56), wide bandwidth (31%), negligible crosstalk (-81dB), and over 40% stretchability. Nine elements are used to cross-locate the structure characteristics within an object based on the flight of time difference. The experimental results demonstrated that the cross-positioning method has over 90% accuracy for object internal characteristics detection. Therefore, our developed stretchable ultrasonic transducer array would have great potential to significantly advance object identification, sorting, and assembly applications in automated robotics.