Ultrasound array provides haptic feedback in mid-air
A research paper by the Interaction and Graphics (BIG) research group on Ultrahaptics is to be presented at the ACM Symposium on User Interface Software and Technology (UIST) 2013 by Tom Carter from the Department of Computer Science.
This uses ultrasonic vibrations for the first time to deliver tactile sensations to the user. The ultrasonic transducer array emits very high frequency sound waves that can be steered by changing the phase and when all of the sound waves meet at the same location at the same time, they create sensations on a human’s skin to provide feedback without having o touch the screen.
By carrying out technical evaluations, the team has shown that the system is capable of creating individual points of feedback that are far beyond the perception threshold of the human hand. The researchers have also established the necessary properties of a display surface that is transparent to 40kHz ultrasound.
The results from two user studies have demonstrated that feedback points with different tactile properties can be distinguished at smaller separations. The researchers also found that users are able to identify different tactile properties with training.
The research team explored three new areas of interaction possibilities that UltraHaptics can provide: mid-air gestures, tactile information layers and visually restricted displays, and created an application for each. Tom Carter, PhD student in the Department of Computer Science’s BIG research group, said: “Current systems with integrated interactive surfaces allow users to walk-up and use them with bare hands. Our goal was to integrate haptic feedback into these systems without sacrificing their simplicity and accessibility.
“To achieve this, we have designed a system with an ultrasound transducer array positioned beneath an acoustically transparent display. This arrangement allows the projection of focused ultrasound through the interactive surface and directly onto the users’ bare hands. By creating multiple simultaneous feedback points, and giving them individual tactile properties, users can receive localised feedback associated to their actions.”