Scientists in Britain say they've develop a technology that uses sound waves to create a "force field" that can simulate the feel of objects in mid-air.

Researchers at Bristol University say their "UltraHaptic" system uses an array of speakers to produce waves of ultrasound aligned to produce an invisible layer of ultrasonic vibrations in the air above a computer display, which can be sensed as tactile sensation of the displayed object on the surface of human skin.

Placed behind a display, the system monitors the motions of a user's fingers above the screen and creates a tactile feedback layer as the user interact with virtual objects like knobs and switches in mid-air.

"By creating multiple simultaneous feedback points, and giving them individual tactile properties, users can receive localized feedback associated to their actions," Bristol computer scientist Tom Carter told The Guardian.

The system allows a user to identify different tactile properties without actually touching anything, he said.

Systems such as Microsoft's Kinect sensor can monitor a user's hand and body motions to allow them to interact with a computer interface but have lacked any sort of tactile feedback.

"Current systems with integrated interactive surfaces allow users to walk up and use them with bare hands," Carter said. "Our goal was to integrate haptic feedback into these systems without sacrificing their simplicity and accessibility."