Ultrasonic array gives touch feedback for gestures in mid air

October 8, 2013 by admin
Filed under: News

A team from the University of Bristol has developed a way to provide feedback from a screen without touching it.

Ultrahaptics in action

The team from the University of Bristol’s Interaction and Graphics (BIG) research group has used a phased array of ultrasonic transmitters to focus high frequency sound onto a target in mid-air. This would be used to provide positive feedback for a gesture-based user interface.

The research paper, to be presented at the ACM Symposium on User Interface Software and Technology (UIST) 2013 by Tom Carter from the Department of Computer Science, will unveil UltraHaptics, using 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. When all of the sound waves meet at the same location at the same time, they create sensations on a human’s skin.

By carrying out technical evaluations, the team have 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.

Finally, 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.”

www.bristol.ac.uk