Spatio-temporal control of vibrotactile stimulation on OLED displays with inverse filtering

This work presents an inverse filter method capable of controlling complex and independent haptic stimulations for up to ten fingers interacting concurrently with a display. Our approach extends the inverse filtering framework to support continuous operation, enabling real-time streaming of multitouch vibrotactile signals while accounting for finger motion. We provide a comprehensive theoretical analysis that establishes the relationship between key design parameters-such as actuator count, display mechanical properties, and finger configuration-and system performance metrics, including vibration amplitude, spatial resolution, stability, and waveform reconstruction error. This analysis offers valuable engineering guidelines for the design of such systems. Our experimental setup showcases the seamless integration of this inverse filtering approach into a commercial off-the-shelf 15.6 inches OLED tactile display, equipped with 16 low-cost piezoelectric patches affixed to the rear. The resulting system can control broadband vibrations at moving positions or playback the vibrations of different musical instruments in a recording. The theoretical insights and practical implementation demonstrated in this work pave the way for advanced haptic feedback systems with broad applications in human-computer interaction and accessible technology.