Changes in Display Surface Shape and Sensory Volume

Tactile displays can reproduce skin sensations, such as the feel of an object's texture and unevenness, and are expected to have a wide range of applications and a promising future. Motion is important because tactile and haptic judgments are made by the fingers. In the skin sensation at the fingertip, the threshold for vibration detection is medically known to range between 10 Hz and 300 Hz. Therefore, in this experiment, Mg was kept constant and the frequency was varied from 1 to 250 Hz. The sinusoidal waveform of the vibrations was produced at eight frequencies: 1, 10, 20, 40, 50, 100, 200, and 250 Hz. The amplitude, Mg, was kept constant at 20μm to 25μm, respectively. The presentation method was set to reproduce the frequencies of the different stimuli on the TouchSense display via random markers, from A to H. The analysis method adopts Nakaya's variant of Scheffé's pairwise comparison method. The questionnaire was distributed to 15 evaluators; each evaluator makes 28 comparisons, representing half of the total number of streets. Roughness ratings were scored on a 5-point scale, and a psychometric scale of roughness perception was thus obtained.