Comparison of Tactile Discriminations to Verify the Undetectable Region of SUS Foil Thickness

Abstract

Understanding human capability in performing critical tasks is key to enhancing sensor performance, especially in robotics. In this study, our objective is to analyze human tactile mechanism behavior in recognizing extremely thin foils using a psychophysics method. Seven pairs of stainless foils ranging in thickness from 20 ~ 150 μm were used in the experiment. We applied the method of constant stimuli to define the difference threshold. In order to increase the detection rate, contact between human tactile function and the metal foils was maintained. As a result, we managed to achieve a similar trend to our previous experimentation. The Weber fraction c reduces as thickness increases and becomes constant with c ≈ 0.4 from t = 120 μm onwards. We also validated the behavior of the undetected regions up to 150-μm thickness. Although duplex theory properties could not be observed, the achievement was quite significant considering the higher thickness test ratio.