One of the side effects of the COVID-19 pandemic and quarantine has been the green light for exotic projects to modernize public spaces to make them hygienically safe. For example, buttons or surfaces that thousands of different people have to touch - what to replace them with? One such project is the HaptiRead technology, which creates Braille lettering right in the air.
At the heart of HaptiRead is a panel of 256 ultrasonic emitters operating at frequencies up to 40 kHz. Since such frequencies are above the human tactile threshold, they are modulated by lower frequencies in the range from 100 to 200 Hz. As a result, the generated air pressure is not only felt by the human skin, but can also be projected at strictly defined points. The area of influence extends to a distance of 70 cm from the panel, the system using Leap Motion technology detects the presence of human hands in this area and projects virtual points directly onto them.
HaptiRead has a low resolution, no more than 8 points are created at the same time, but there is no confusion with their recognition. The main difficulty was the method of displaying information, of which there were three. In the first method, all points in the cell are drawn at once, in the second they are displayed sequentially, and in the third, each point is projected separately. According to the results of testing on sighted and blind people, it was the last method that was named the most convenient - it is not fast, but informative. Signal recognition accuracy was 94% for sighted people and 88% for blind people.
The HaptiRead technology is not yet ready for use, it is in development. But the advantages are obvious - air messages exclude the touch of hands to surfaces, the risk of infection or simply getting dirty. And if you combine ultrasonic emitters with holograms, you can create a new kind of multichannel interfaces.