Human-Interactive, Active-Matrix Displays for Visualization of Tactile Pressures

Human-interactive displays involve the interfacing of a stimuli-responsive sensor with a human-readable response. Human-readable responses include the five recognized senses, i.e., sight (vision), hearing (audition), taste (gustation), smell (olfaction), and touch (somatosensation). Vision is considered to be the most informative human stimulus so that the visualization of electrical, thermal, and mechanical data is important for various applications. Herein, the fabrication of human-interactive displays is demonstrated in which active-matrix arrays of pressure-sensitive Si transistors with air dielectric layers are fully integrated with pixels of organic light-emitting diodes (OLEDs). In this way, the luminance of the individual OLED pixels can be increased locally by pressing the display, and the luminance is dependent on the magnitude of the applied pressure. Furthermore, the air dielectric layer of transistors provides outstanding electrical properties, including high transconductance and negligible hysteresis. 3D integration of these transistors with dual-side emissive OLED pixels is also demonstrated. Local pressing increases the light intensity of OLED pixel and then the underlaid Si channel can absorb this light successively to generate additional photocurrents from the pressure-sensitive transistor, further enhancing its sensitivity. This human-interactive display can visualize tactile pressure directly, suggesting the substantial promise as next generation displays for intelligent human-machine interfacing.