SBIR Phase II: Electrostatic Normal Force Modulation for Haptic Touch Screens

This Small Business Innovation Research (SBIR) Phase II project will advance the development of electrostatic surface haptics as a means of providing tactile feedback for touchscreens. In electrostatic surface haptics, a user's finger(s) are selectively pulled down to a glass surface by an electrostatic potential, just as a capacitor's plates are attracted to one another. The enhanced normal force leads to an enhanced frictional force when the fingers are moved across the surface. By modulating the electrostatic force in response to finger position and time, a great variety of compelling haptic percepts can be created. In previous work, low voltage techniques, thin hard high dielectric coatings, a way of avoiding the necessity of grounding the user, patterns of transparent conductor that allow different fingers to experience different sensations, and some of the software controls, were developed. In Phase II, methods of finger position sensing that are fully compatible with haptic actuation will be developed. The new methods also offer the possibility of discriminating multi-touch fingers according to same or opposite hand, or the fingers of a second person on the same touchscreen. The broader impact/commercial potential of this project stems from enriched communication with touchscreen devices. Already touchscreens are of immense commercial importance. The worldwide market for touchscreen modules grew three-fold from 2009 to 2011 with smartphones, tablet computers, and automotive display applications leading the charge. Consumers have been attracted to the versatility of touchscreens as input devices, yet the absence of haptic feedback has limited accessibility for low-vision populations, exacerbated safety concerns in applications such as driving, and prohibited the aesthetics of touch from being fully developed. Surface haptics technology has the potential to address all of these weaknesses. It can be used to make user interface elements operable by touch alone, to create new interaction metaphors, and to enhance the overall user experience. By addressing known and latent needs in the marketplace, surface haptics will foster new industrial growth.