One of the challenges in the field of haptics is to provide meaningful and realistic sensations to users. While most real world tactile sensations are composed of multiple dimensions, most commercial product only include vibration as it is the most cost effective solution. To improve on this, we introduce VPS (Vibration, Pressure, Shear) display, a multi-dimensional tactile array that increases information transfer by combining Vibration, Pressure, and Shear similar to how RGB LED combines red, blue, and green to create new colors. We characterize the device performance and dynamics for each tactile dimension in terms of its force and displacement profiles, and evaluate information transfer of the VPS display through a stimulus identification task. Our results indicate that the information transfer through a single taxel increases from 0.56 bits to 2.15 bits when pressure and shear are added to vibrations with a slight decrease in identification accuracy. We also explored the pleasantness and continuity of VPS and the study results reveal that tactile strokes in shear mode alone are rated highest on perceived pleasantness and continuity.
Each VPS taxel consits of a voicecoil and a DC motor. Voicecoil is used to provide vibration and pressure, while DC motor generates shear sensations.
VPS array with drivers
To increase the information bandwidth, we combined 4 VPS taxels in a row to enable generation of stroke-like sensations along user's forearem.
We performed user evaluations for both a single VPS taxel and an array of them.
We see an increase in information trasnfer with additional tactile dimensions. However, there seems to be an upper limit as there is no significant increase from two dimensions to three dimensions.