Modeling, fabrication, and testing of a MEMS multichannel aln transducer for a completely implantable cochelar implant

An implantable acoustic transducer is crucial for a completely implantable cochlear implant (CICI). This paper presents a miniaturized multichannel aluminum nitride (AlN) transducer designed to fit inside a guinea pig cochlea and act as a front end of a CICI. The transducer, fabricated using microelectromechanical systems techniques, has four piezoelectric bimorphs to produce broadband enhanced sensitivity. Transducer functionality is demonstrated via in-air and underwater actuation and acoustic sensing. A finite element analysis model is developed to design the transducer and understand its frequency behavior. The modeled results provide a good match with the experimental results.