Flexible Ultrasonic Transducer for RF-Data and Energy Transmission Through the Metal Pipe

Using battery less sensor module to monitor the environmental condition inside the metal pipes is one of the highly demanding and challenging research topics in industry. In this paper a flexible ultrasonic transducer by application of 12 (3X4) thinned piezoceramics with the thickness of 195 μm has been proposed for RF-Data and energy transmission through the metal pipe with the thickness of 1 cm. The main idea is utilizing near field communication (NFC) technology with center frequency of 13.56 MHz by replacement of RF-antenna with array of PZTs to monitor the internal condition of the metal pipe in the detachable method. By application of the proposed flexible transducer, it is possible to transmit 60 mW energy from detachable NFC-reader to the transponder side which is placed in the non-accessible side of metal pipe. Additionally, the process flow of fabrication of flexible array of 3X4 piezoceramic is presented. According to the simulation and experimental results, the power transmission efficiency has been enhanced by 3 % and the bandwidth is extended by 80 %.