Multi-channel thin film piezoelectric acoustic transducer for cochlear implant applications

This paper presents a multi-channel piezoelectric acoustic transducer that is working within the audible frequency band (250- 5500 Hz). The transducer consists of eight cantilevers with thin film PLD-PZT piezoelectric layers. The transducer is well suited to be implanted in middle ear cavity with an active volume of 5x5x0.6 mm(3) and mass of 4.8 mg excluding the test frame. Finite Element Method (FEM) is used for modelling cantilever resonance frequencies and piezoelectric outputs. This model and shaker-table experiments are in good agreement on the frequency (97%) and output voltage (89%) values. Transducer can generate up to 139.36 mV(pp) under 0.1 g excitation at 316 Hz, which is the highest reported output voltage from a piezoelectric acoustic sensor to the best of our knowledge