Array force display for hardness distribution

This paper describes design of array force display for presentation of hardness distribution in an elastic object. The array force display is composed of an elastic plate and a linear actuator array. It provides a spatially continuous surface on which users can effectively touch virtual objects using any part of their bare hand. The elastic plate is made of rubber and sponge. When the actuator pushes the plate, its hardness increases. The user feels as if hard object is submerged in a soft object. The device is evaluated through experiments for palpation performance.