Flat Panel Haptics: Embedded Electroosmotic Pumps for Scalable Shape Displays

Abstract

Flat touch interfaces, with or without screens, pervade the modern world. However, their haptic feedback is minimal, prompting much research into haptic and shape-changing display technologies which are self-contained, fast acting, and offer millimeters of displacement while only being only millimeters thick. We present a new, miniaturizable type of shape-changing display using embedded electroosmotic pumps (EEOPs). Our pumps, controlled and powered directly by applied voltage, are 1.5mm in thickness, and allow complete stackups under 5mm. Nonetheless, they can move their entire volume's worth of fluid in 1 second, and generate pressures of +/-50kPa, enough to create dynamic, millimeter-scale tactile features on a surface that can withstand typical interaction forces (<1N). These are the requisite technical ingredients to enable, for example, a pop-up keyboard on a flat smartphone. We experimentally quantify the mechanical and psychophysical performance of our displays and conclude with a set of example interfaces.