5.3 Biomimetic Acoustic Sensors

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Figure 5.5: Magnetic nanoparticles are used to control the opening and closing of the MET ion chan-

nels connected to hair cells at time scales that varied from a few seconds to 100 µs (adapted from [7]).

(a) Schematic drawing and microscope image of a magnetic probe activating a single hair bundle.

(b) Schematic diagram of the EM probe stimulating a single hair bundle with magnetic particles. (c) Mo-

tion of a single hair bundle deflected by the EM probe. Black line: tracked bundle displacement, red line:

current applied to the EM probe. Application of (i) static and (ii) 5 Hz square wave current. (d), (e) Varying

frequency stimulation. (f) Fourier transform spectra of oscillation shown in (e). (g) FT spectrum of bundle

motions at 10 000 Hz.

5.3 Biomimetic Acoustic Sensors

The most common biomimetic (nano) technology for hearing is the microphone. It con-

tains a diaphragm, which mimics the eardrum of the oval window, which vibrates ac-

cording to the sound in the environment. The mechanical movement of the diaphragm

is then converted into an electrical signal. The diaphragm could be part of a plate capac-