A Portable One-Hand Braille Input System Enabled by Dual-Interlocked Tactile Sensors for Communication

This article presents a novel portable one-hand Braille input system (BIS) to assist visually impaired users in entering text on electronic devices. The proposed BIS is designed based on a flexible Braille keyboard (FBK), it mainly consists of five dual-interlocked tactile sensors, a processing circuit, and a software modulus. The fully elastomeric graphene/carbon nanotube/silicone rubber nanocomposites are synthesized and used as tactile sensing material and polydimethylsiloxane (PDMS) as the structural and encapsulation for the fabrication of sensors. Characterization tests showed the tactile sensor has relatively high force sensing sensitivity of 0.649 N-1 at sensing range of 0-5 N and a frequency sensing ability of 0.5-2.0 Hz, which can meet human finger pressing requirements. A specific Braille input method is proposed, and personalized parameters are set for users to fit different pressing habits. The average input speed of 3.37 words per minute (WPM) with an average accuracy of 92.2% for Braille characters input is demonstrated by evaluating text entry performance. The results indicated that our developed tactile sensor enabled portable one-hand BIS can assist visual impaired users with enhanced text entry on electronic devices effectively and privately.