Thin film piezoelectric acoustic transducer for fully implantable cochlear implants

2018-09-01
Ilık, Bedirhan
Koyuncuoglu, Aziz
Sardan-Sukas, Ozlem
Külah, Haluk
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 (SPL) at 1325 Hz. This is the highest value for a thin film piezoelectric transducer in the literature to our knowledge. Using the results of a finite element analysis for this single-channel prototype, which are within 92% agreement with the experimental results, we performed an optimization study to propose a multi-frequency acoustic sensor to be placed on the eardrum for fully-implantable cochlear implant (FICI) applications. The proposed multi-channel transducer consists of eight cantilever beams. Each of these beams resonates at a specific frequency within the daily acoustic band (250-5000 Hz), senses the eardrum vibration and generates the required voltage output for the stimulation circuitry. The total volume and mass of the transducer are 5 x 5 x 0.2 mm(3) and 12.2 mg, respectively. High sensitivity of the transducer (391.9 mV/Pa @900 Hz) enables transmission of strong signals to be the readout circuit, which can easily be processed. Expected to satisfy all the requirements (volume, mass, and stimulation signal at the hearing band) of FICI applications for the first time in literature, the proposed concept has a groundbreaking nature and it can be referred to as the next generation of FICIs since it revolutionizes the operational principle of conventional Cls. (C) 2018 The Authors. Published by Elsevier B.V.
SENSORS AND ACTUATORS A-PHYSICAL

Suggestions

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 (2017-09-06)
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 ou...
Symmetrical and decoupled nickel microgyroscope on insulating substrate
Alper, Se; Akın, Tayfun (Elsevier BV, 2004-09-21)
This paper presents a symmetrical and decoupled surface micromachined gyroscope fabricated by electroforming thick nickel on a glass substrate. The symmetric structure allows matched resonant frequencies for the drive and sense vibration modes for improved sensitivity, while the decoupled drive and sense oscillation modes prevents unstable operation due to mechanical coupling, resulting in a low zero-rate output drift. The use of a glass substrate instead of a silicon substrate reduces noise due to the para...
Nonlinear free vibrations of curved double walled carbon nanotubes using differential quadrature method
Ciğeroğlu, Ender (Elsevier BV, 2014-11-01)
Nonlinear free vibration analysis of curved double-walled carbon nanotubes (DWNTs) embedded in an elastic medium is studied in this study. Nonlinearities considered are due to large deflection of carbon nanotubes (geometric nonlinearity) and nonlinear interlayer van der Waals forces between inner and outer tubes. The differential quadrature method (DQM) is utilized to discretize the partial differential equations of motion in spatial domain, which resulted in a nonlinear set of algebraic equations of motion...
Tunable dual-frequency RF MEMS rectangular slot ring antenna
Topalli, Kagan; Erdil, Emre; Aydın Çivi, Hatice Özlem; Demir, Şimşek; Koç, Seyit Sencer; Akın, Tayfun (Elsevier BV, 2009-12-01)
This paper presents the design, fabrication, and measurement of a novel, tunable, dual frequency rectangular slot antenna using RF MEMS technology. The antenna tuning is achieved by electrostatically actuated RF MEMS variable capacitors on a stub. Two different capacitor structures are implemented on the antenna: cantilever type and fixed-fixed beam type. The latter one is not sensitive to the stress on the structural layer and its measurement results agree well with the simulation results. Each antenna is ...
Quantum Transport Mode in Graphene Nanoribbon Based Transistor
Hedayat, Sayed Norollah; Ahmadi, Mohammad Taghi; Sedghi, Hassan; Goudarzi, Hadi; Moradi, Shahram (American Scientific Publishers, 2017-09-01)
Graphene has incredible carrier transport property with high application opportunity at single molecule level, which composes it as promising materials on nano electronic application. In order to develop the new device such as graphene nanoribbon transistor, Carbon Nanotube Field Effect Transistor (CNTFET) and nanowire based devices, it is essential to investigate the quantum limit in low dimensional systems. In this paper transmission coefficient of the schottky structure in the graphene based transistor i...
Citation Formats
B. Ilık, A. Koyuncuoglu, O. Sardan-Sukas, and H. Külah, “Thin film piezoelectric acoustic transducer for fully implantable cochlear implants,” SENSORS AND ACTUATORS A-PHYSICAL, pp. 38–46, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/35612.