Accession Number : ADA299948

Title :   Biomimicking: Electro-Elastic Structural Speciality in Auditory Receptor Cells.

Descriptive Note : Final rept. 15 May 92-14 May 95,

Corporate Author : STANFORD UNIV CA DEPT OF APPLIED MECHANICS

Personal Author(s) : Steele, Charles R.

PDF Url : ADA299948

Report Date : 16 SEP 1995

Pagination or Media Count : 3

Abstract : A recent discovery is that certain receptor cells in the cochlea in the inner ear undergo displacement due to an electric field, for frequencies as high as 25 kHz in the guinea pig. In the hearing process, these cells are likely to provide the important feedback mechanism for the enhancement of low amplitude sound. Part is due to the unique microstructural design of the wall of the cell, consisting of a passive elastic cytoskeleton and an isotropic piezoelectric membrane. Using measurements from several laboratories permitted the calculation of the orthotropic piezoelectric properties of the wall. With our measurements, the elastic moduli of the protein components in the cytoskeleton were determined Computations of the dynamic response of the whole cell containing and immersed a viscous fluid agree fairly well with experiments. Despite the small cell size, small in comparison with the viscous boundary layer, the orthotropic design permits the cell to delivery significant force with low electric signal at auditory frequencies. Possible application of the design to devices is being pursued.

Descriptors :   *ELASTIC PROPERTIES, *EAR, *COCHLEA, FIBERS, MICROSTRUCTURE, COMPUTATIONS, PROTEINS, DYNAMIC RESPONSE, MODULUS OF ELASTICITY, PASSIVE SYSTEMS, BOUNDARY LAYER, ELECTRIC FIELDS, INTERNAL, FEEDBACK, SIGNALS, ISOTROPISM, PIEZOELECTRIC MATERIALS, SOUND, ELECTRIC POWER, MEMBRANES, FLUIDS, AMPLITUDE, VISCOUS FLOW, VISCOSITY, PIEZOELECTRIC EFFECT, HEARING, SENSE ORGANS, CELL STRUCTURE, GUINEA PIGS, AUDITORY NERVE, COCHLEAR NERVE.

Subject Categories : Anatomy and Physiology
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE