Measurement of Young's Modulus of Human Tympanic Membrane at High Strain Rates

The mechanical behavior of human tympanic membrane (TM) has been investigated extensively under quasistatic loading conditions in the past. The results, however, are sparse for the mechanical properties (e.g., Young's modulus) of the TM at high strain rates, which are critical input for modeling the mechanical response under blast wave. The property data at high strain rates can also potentially be converted into complex modulus in frequency domain to model acoustic transmission in the human ear. In this study, we developed a new miniature split Hopkinson tension bar to investigate the mechanical behavior of human TM at high strain rates so that a force of up to half of a newton can be measured accurately under dynamic loading conditions. Young's modulus of a normal human TM is reported as 45.2-58.9 MPa in the radial direction, and 34.1-56.8 MPa in the circumferential direction at strain rates 300-2000 s(-1). The results indicate that Young's modulus has a strong dependence on strain rate at these high strain rates.