An airborne ultrasound tactile display (AUTD) can focus on an arbitrary position by controlling the phase shift and amplitude of each transducer, and provide a tactile stimulus on the human body without direct contact. However, beyond a distance from the phased array, it cannot secure a focal size comparable to the wavelength and the displayed pressure pattern blurs. In this study, we propose a method with a concave reflector to focus at a farther position and present a tactile sensation without enlarging the array. By appropriately designing the focal length of the concave reflector, the focal point can be formed at a distant position using a mirror formula while keeping the focus size non-extended. We conducted two experiments, the results of which show that the proposed method is valid and that a workspace of several square centimeters can be achieved.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.