단차에 대한 촉각 인지 역치 측정

The presence of steps on the surface of a product is a typical example of deteriorating product quality. Therefore, it is required to lower their heights to a level that a human cannot perceive. In this context, the present study focuses on experimentally measuring the minimum perceptible step height (absolute threshold). For this purpose, step samples with heights less than 3 μm were made from silicon wafers using a microelectromechanical systems (MEMS) fabrication technique with an accuracy under 10 nm. The experiment was performed using the method of constant stimuli. The participants were instructed to touch the samples using their index fingers, and then answer whether they perceived the steps or not. After analyzing the data statistically, it was concluded that the absolute threshold is about 1.35 μm when the finger moves in the direction parallel to the finger and about 2.04 μm in the direction perpendicular to the finger.