MEMS-based cochlear implant

An energy-harvesting, fully implantable cochlear implant system for providing electrical stimulation signals, comprising:

• an acoustic transducer including frequency-selective piezoelectric cantilevers configured to generate electrical signals for neural stimulation, the acoustic transducer comprising a plurality of cantilever beams and a piezoelectric piece bonded to each of the cantilever beams;
• wherein each of the plurality of cantilever beams has a different predetermined natural frequency corresponding to a 200 Hz-10 KHz frequency band of the incoming acoustic waves,
• an autonomous interface electronics that comprises passive and active circuits with two storage elements including a capacitor and a rechargeable battery and that manages the extracted energy and provides regulated supplies for stimulation electronics and is configured to connect to the acoustic transducer and to receive and amplify the signals of the plurality of cantilever beams;
• and process circuits to stimulate auditory nerves through cochlear electrodes,
• an energy-harvesting system comprising a piezoelectric cantilever configured to extract incoming acoustic energy available in the auditory system,
• a power-conditioning interface circuit configured to extract energy from the energy-harvesting system and to supply regulated power to the autonomous interface electronics,
• a wireless power transmission interface circuit configured to provide a back-up and supporting energy source to the energy-harvesting system, the rechargeable battery configured to be implanted under the skin and recharged by the energy-harvesting system, at least one radio-frequency (RF) coil usable for wireless transfer, patient fitting, and recharging the rechargeable battery via an external radio-frequency coil alignable with an implanted radio-frequency coil;
• and
• wherein each of the plurality of cantilever beams is designed to have a predetermined natural frequency;
• wherein a low-frequency cantilever beam incorporates a tip mass on the free end and high-frequency cantilever beams are free of the tip mass.