Handheld Haptic Interface for Rendering Size, Shape, and Stiffness of Virtual Objects.

PaCaPa is a handheld device that presents haptic stimuli on a user's palm when the user interacts with virtual objects using virtual tools. It is a box-shaped device and has two wings. This device can present the contact force and contact angle by opening and closing the wings based on the angle between the direction of the virtual tool and hand. By changing these haptic sensations on the palm and fingers, it enables the users to perceive different size, shape, and stiffness of virtual objects.