Influence of the indentation speed on viscoelastic behavior of the human finger

Abstract

In this paper the authors presented a methodology to study the viscoelastic behavior of the human finger tissue by using the indentation process with a steel ball and indentation speed between 0.02 mm/s to 4 mm/s. Considering that at very low speeds the viscoelastic effects can be neglected, an effective Young’s modulus of the human finger as function of the indentation force was determinate based on the Hertzian equation and validated with experimental data. The influence of the indentation speed on both, the indentation force and depth, was studied and a mathematical model was proposed. The authors observed that the normal force resulting from the indentation process increase with speed due to an important damping effect in the finger tissue. Also, based on the Hertzian contact model the contact pressure during the indentation process has been calculated.