Thin Film PZT Acoustic Sensor for Fully Implantable Cochlear Implants

İlik, Bedirhan
Koyuncuoğlu, Aziz
Uluşan, Hasan
Chamanıan, Salar
Işık Akçakaya, Dilek
Şardan Sukas, Özlem
Külah, Haluk
This paper presents design and fabrication of a MEMS-based thin film piezoelectric transducer to be placed on an eardrum for fully-implantable cochlear implant (FICI) applications. Resonating at a specific frequency within the hearing band, the transducer senses eardrum vibration and generates the required voltage output for the stimulating circuitry. Moreover, high sensitivity of the sensor, 391.9 mV/Pa @900 Hz, decreases the required power for neural stimulation. The transducer provides highest voltage output in the literature (200 mVpp @100 dB SPL) to our knowledge. A multi-frequency piezoelectric sensor, covering the daily acoustic band, is designed based on the test results and validated through FEA. The implemented system provides mechanical filtering, and mimics the natural operation of the cochlea. Herewith, the proposed sensor overcomes the challenges in FICI operations and demonstrates proof-of-concept for next generation FICIs.


Multi-channel thin film piezoelectric acoustic transducer for cochlear implant applications
YÜKSEL, MUHAMMED BERAT; İlik, Bedirhan; Koyuncuoğlu, Aziz; Külah, Haluk (2019-10-27)
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-tab...
Thin film piezoelectric acoustic transducer for fully implantable cochlear implants
Ilık, Bedirhan; Koyuncuoglu, Aziz; Sardan-Sukas, Ozlem; Külah, Haluk (Elsevier BV, 2018-09-01)
This paper reports the development of a single cantilever thin film PLD-PZT transducer prototype. The device was experimentally characterized by attaching it on an acoustically vibrating membrane resembling the behavior of the eardrum. Acceleration characteristic of the sensor attached on the membrane was obtained by using a Laser Doppler Vibrometer (LDV) as the output voltage was measured by an oscilloscope. A voltage output of 114 mV was obtained, when the device was excited at 110 dB Sound Pressure Level...
Thin-Film PZT based Multi-Channel Acoustic MEMS Transducer for Cochlear Implant Applications
Yüksel, Muhammed Berat; Külah, Haluk (2021-01-01)
AuthorThis paper presents a multi-channel acoustic transducer that works within the audible frequency range (250-5500 Hz) and mimics the operation of the cochlea by filtering incoming sound. The transducer is composed of eight thin film piezoelectric cantilever beams with different resonance frequencies. The transducer is well suited to be implanted in middle ear cavity with an active volume of 5 mm × 5 mm × 0.62 mm and mass of 4.8 mg. Resonance frequencies and piezoelectric outputs of the bea...
MEMS thin film piezoelectric acoustic transducer for cochlear implant applications
İlik, Bedirhan; Külah, Haluk; Department of Electrical and Electronics Engineering (2018)
In this thesis, a multi-frequency thin film piezoelectric acoustic sensor concept to be placed on the eardrum has been proposed for the development of next generation and fully implantable cochlear implants (FICIs). The design consists of several thin film piezoelectric cantilever beams, each of which resonates at a specific frequency within the daily acoustic band. The device will exploit the functional parts of the natural hearing mechanism and mimic the function of the hair cells in the cochlea, where th...
Fully Implantable Cochlear Implant Interface Electronics With 51.2-mu W Front-End Circuit
Ulusan, Hasan; Chamanian, Salar; Ilik, Bedirhan; Muhtaroglu, Ali; Külah, Haluk (2019-07-01)
This paper presents an ultralow power interface circuit for a fully implantable cochlear implant (FICI) system that stimulates the auditory nerves inside cochlea. The input sound is detected with a multifrequency piezoelectric (PZT) sensor array, is signal-processed through a front-end circuit module, and is delivered to the nerves through current stimulation in proportion to the sound level. The front-end unit reduces the power dissipation by combining amplification and compression of the sensor output thr...
Citation Formats
B. İlik et al., “Thin Film PZT Acoustic Sensor for Fully Implantable Cochlear Implants,” 2017, vol. 1, Accessed: 00, 2020. [Online]. Available: