Rendering Softness Using Airborne Ultrasound

Abstract

In this paper, we propose a method for reproducing the tactile sensation of touching a soft object via an ultrasound transducer array. This method simulates the collision of a soft object with a mesh model of a finger, created from a point cloud obtained via depth cameras, and optimizes the phases of the transducers to reproduce the pressure distribution calculated from the simulation. The relationships between force, indentation depth, and contact area at the fingertip are thought to be key for human perception of softness. Through numerical simulations, it is shown that the pressure distribution relationship reproduced by our method is similar to that of touching an actual soft object. In addition, we conducted a user study to verify that our method is capable of representing discriminable softness.