People who are blind need to touch surfaces and materials to get information. These surfaces can be a Braille paper that has Braille text, a swell paper that has embossed shapes, and a button that is used to turn on and off a device like a TV or to open a train carriage door. Due to Covid-19, hygienic practices will be more and more important, and it will be very restrictive for people who are blind to touch surfaces in public places. Mid-air haptics interfaces can potentially be used in public places or in community areas to provide information and to operate devices without touching a surface.

In this study, we want to investigate the use of mid-air haptics to provide visual information. Mid-air haptics interfaces use an array of tiny speakers to generate ultrasonic waves up in the air. These waves can be programmed in a way that it can create acoustic pressure areas that can be sensed as an air flow on the palm or finger tips.