Rayleigh waves in thermally affected skin tissues based on age, gender and morphology.

The present work studies the variation in the nature of Rayleigh waves due to change in age, gender and morphological region of human skin tissue in the context of three-phase-lag (TPL) nonlocal thermoelastic theory. The secular equations are derived using the stress free, thermally insulated or isothermal boundary conditions. These secular equations are solved numerically and two significant modes of Rayleigh wave are noted to propagate simultaneously. The phase speeds, attenuation coefficients and path of the particle motion for both modes are presented graphically. These results are compared for different age, gender and morphological region of the source skin tissue. We have observed that the phase speeds increase with the increases of stiffness of the skin and vice versa. Certain specific angular frequencies and phase speeds are obtained which can be used for the detection and thermal therapy of skin disorders. Some published results are recovered as special cases to validate the current results.