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Updated: Jun 28, 2026

Optogenetic Stimulation of the Auditory Nerve
Published on: October 8, 2014
A novel opto-electromagnetic actuator coupled to the tympanic membrane
Chia-Fone Lee1, Chih-Hua Shih, Jen-Fang Yu
1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
Abstract:
A new type of electromagnetic vibration transducer designed to be placed onto the tympanic membrane was developed. The actuator consisted of two photodiodes, two permanent magnets, an aluminum ring, two opposing wound coils, a latex membrane and a Provil Novo membrane. An optic probe was designed to allow sound and light signals to enter the ear canal, thereby preventing the acoustic occlusion effect of traditional ear molds. Two light-emitting diodes were used for carrying the input signals. The corresponding photodiodes were used for receiving the light signals and generating currents in the actuator. The opto-electromagnetic vibration actuator was fabricated and tested using a Laser Doppler vibrometer. The actuator showed displacements of vibration between 30 and 1 nm from 300 to 6500Hz and reduced in amplitude at higher frequencies. The average gain of the actuator with 140microA on the umbo displacement was about 20 dB relative to 87 dBA at the distance of 6cm from the tympanic membrane and 0microA in actuator.
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