Extending Dynamic Blind Interaction: Microgap Discharge-Induced Flexible Virtual Electrotactile Braille

Braille is an essential implement for the blind to communicate with outside, but traditional Braille is limited to a paper-based format that cannot directly provide real-time word information. In this work, a flexible virtual electrotactile Braille is proposed that can benefit the blind from blocked interaction. The Braille interface, S-shaped wires and a sphere electrode with a textile fingerstall integrated by silicone, offers flexibility and simultaneously generates the microgap through textile cracks, which achieves virtual electrotactile sensation by electrostatic discharge. Powered by a high-voltage triboelectric generator of 10.2 kV designed through the charge accumulation and induction strategy, the electrotactile stimulation is realized with a microgap discharge of only 40 μA current induced on the finger. A dynamic electrotactile Braille is finally assembled, controlled by a programmable relay array. The strategies of short circuit and voice reminder are employed, so that the recognition of dynamic Braille letters is realized with spatiotemporal electrotactile stimulation and high recognition accuracy. This virtual electrotactile Braille brings convenience for the blind to access the information world and illustrates its applications to promote virtual electrotactility in this special community.