Design of electrotactile stimulation to represent distribution of force vectors

Transmission of the distribution of force vectors on a fingertip improves the stability of a given operation in a tele-operation system. As such, we seek the representation of the distribution of force vectors via an electrotactile display. The electrotactile display directly activates nerve fibers connected to mechanoreceptors, thereby representing a tactile sensation. The system has a simple structure, is easily controlled and, it has seen a number of different applications. However, the majority of the conventional electrotactile displays only present a symbolic sensation of contact. In this paper, we propose the design of electrotactile stimulation for the distribution of force vectors, on the basis of the concept of "tactile primary colors". Considering that a selective stimulation of mechanoreceptors enables the representation of the distribution of force vectors, we evaluate the proposed design in terms of the distribution, magnitude, and direction of a force vector. The results demonstrate that the proposed design is a viable approach to representing the distribution of force vectors.