Surface haptics: Virtual touch on physical surfaces

Summary form only given. The touch screen is the preeminent human-computer interface of our times. With the benefit of market pull, touch input technologies (e.g., projected capacitance and multi-touch) are rapidly advancing. But what about touch output? In this talk, I'll discuss “surface haptics”: programmable haptic interaction for physical surfaces such as touch screens and touch pads. Four main approaches - vibration, shape, electrotactile, and shear force - will be reviewed, but emphasis will be given to shear force because it is uniquely suited to bilateral (e.g., force feedback) interaction. I'll explain how shear force can be controlled by manipulating friction. Specific approaches to controlling coefficient of friction (μ), normal force (N), and relative velocity (Δv), will be reviewed, and I'll describe a variety of devices - the TPaD, ShiverPaD, SwirlPaD, and ActivePaD - that have been developed in our lab to exploit these effects. I'll share some recent experimental results, and close with some speculation on the future of surface haptics.