Magnetic Tactile Sensor for Braille Reading

We report a biomimetic magnetic tactile sensor for reading Braille characters. The sensor consists of magnetic nanocomposite artificial cilia implemented on magnetic micro sensors. The nanocomposite is produced from the highly elastic polydimethylsiloxane and iron nanowires that exhibit a permanent magnetic behavior. This design enables remote operation and does not require an additional magnetic field to magnetize the nanowires. The highly elastic nanocomposite is easy to pattern, corrosion resistant, and thermally stable. The tactile sensors can detect vertical and shear forces, which allows recognizing small changes in surface texture, as in the case of Braille dots. The six dots of a braille cell are read from top to bottom with a tactile sensor array consisting of four elements and 1 mm long nanocomposite cilia.