Human sensitivity to height differences in textured surfaces is on the order of microns. Research on human texture perception requires texture samples with precisely controlled micro-geometry. This can be achieved with an electrical discharge machining (EDM) procedure, but the process is time consuming and labor intensive. An alternative approach is to simulate textured surfaces with a haptic interface with high position resolution. The present study measured the amplitude discrimination thresholds for surfaces with triangular gratings using real EDM textured samples and virtual textures rendered with a highprecision force-feedback device called the ministick. The results indicated that the just noticeable differences for real and virtual textures, respectively 3.69±0.65 and 4.94±0.96 μm, were of similar magnitude. Therefore, we propose that this device is suitable for the study human perception of surface micro-geometry with features on the scale of human perceptual resolution.
Matthew Kocsis, Hong Z. Tan, Bernard D. Adelstein