Wearable Finger Pad Sensor for Tactile Textures Using Propagated Deformation on a Side of a Finger: Assessment of Accuracy

Measuring the shear deformation of a finger pad during active hap tic exploration of materials is important for analysis of textural sensations and development of tactile texture displays. Thus far, there has been no general methods to measure such deformations for active touch. To create a sensor system, we have been developing a new method for estimating the deformation of a finger pad based on the skin deformation propagated to the radial side of a finger tip. In this study, in order to validate the method, we compared the deformation or its acceleration of finger pad estimated on the basis of the acceleration measured at the radial side and those estimated by the shear force applied to the finger pad while exploring a few types of materials. The estimation errors for the deformations at 40 -- 450 Hz were smaller than human discrimination thresholds, indicating that the accuracy of our method is satisfactory compared with human perceptual sensitivity.