Vibrotactile feedback in delicate virtual reality operations

Virtual environments are often unsuitable for delicate operations because of the poverty of feedback, particularly tactile and force feedback. However, force feedback done properly requires large, heavy, expensive equipment. We have experimented with a particular form of tactile feedback using vibration as a substitute for force feedback. Substituting vibration for force feedback is intuitively appealing because it is cheap and low cost. But is it effective? Unfortunately, the answer is both "yes" and "no". We describe an experiment evahtating the effect of vibrotactile sensory substitution on user performance during a grasping task with delicate virtual objects. We found that adding vibrotactile feedback to visual and audio feedback improved task completion time for novice users, but led to increased grasp pressure over repeated uses of the system.