EMFi-based ultrasonic transducer for robotics applications

A prototype of an ultrasonic transducer based on electromechanical film (EMFi) is presented, as well as its electronic driving and receiving blocks. The electromechanical film provides a wide bandwidth response, showing enough of a level of sensitivity to allow echo-pulse measurement in the most frequency ranges for robotics applications. Emission patterns are obtained, verifying the correspondence between experimental data and the theoretical piston model. Experimental results show that the EMFi-based transducer can be used as a broadband ultrasonic transducer, allowing transmission from 20 to 200 kHz. The wide bandwidth provided by the transducer is a remarkable advantage for sensor systems using encoded ultrasonic signals with wideband modulation schemes, which require considerably more bandwidth than what conventional transducers allow. In this way, main lobes can be discriminated more easily from sidelobes and crosstalk interference can be reduced.