Characterization of surfaces virtually created using MEMS tactile display

In this paper, we report on the creation of a virtual surface using a MEMS tactile display and its quantitative analysis. The display consists of 3 x 3 large-displacement MEMS actuators with hydraulic amplification mechanisms. The MEMS tactile display that we developed can create virtual surfaces that generate various tactile feelings at human fingertips by controlling the displacement, vibration frequency, and period of actuation of the actuators. To quantitatively characterize the virtually created surfaces, we newly proposed a sample comparison method. We compared the tactile feelings with those of 18 samples, such as wood, urethane foam, and sandpaper. These samples were characterized with respect to roughness and hardness using a laser microscope and a compression testing machine. The subjects were requested to select one of these samples that had a tactile texture most similar to the one created by the tactile display. From the experimental results, we could deduce a relationship between the driving conditions of the actuators and the roughness and hardness of the selected samples, and thus, the virtually created surfaces. We experimentally found that the displacement of actuators had a strong correlation with roughness whereas the display created hard surfaces under the tested driving conditions. (C) 2014 The Japan Society of Applied Physics