Resonance Frequency Selective Electromagnetic Actuation for High-Resolution Vibrotactile Displays

Vibrotactile displays offer significant potential for conveying information through the sense of touch in a wide variety of applications. Spatial resolution of these displays is limited by the large size of actuators. We present a new selective electromagnetic actuation technique to control the vibrations of multiple tactile elements using a single coil based on their individual mechanical resonance frequencies. This technique allows low-cost and highly reliable implementation of many tactile elements on a smaller area. A prototype is manufactured using 3D-printed tactile elements and off-the-shelf coils to characterize the proposed technique. This prototype successfully increases the resolution by 100 % from 16 to 32 tactile pixels (taxels) on a 25 cm² pad, without sacrificing other performance metrics such as refresh rates and power consumption. The multiphysics finite element analysis developed for this new actuation technique are experimentally validated by optical vibrometry measurements. This work demonstrates the capability of resonance-selective electromagnetic actuator in developing high-resolution low-cost vibrotactile displays.