VOA常速英语:Scientists Create 'Touchable' Virtual Objects

Technology is already capable of tricking most of our senses ... laser holography can create three-dimensional images where nothing exists, stereo sound can surround us, and smells can be infused into the air. Now, scientists are starting to break the next barrier - the sense of touch.

Scientists at a British university have developed a device that makes our hands feel objects that are not there.

Motion recognition technology already allows users to command computer-controlled devices by waving a hand above a sensitive surface. But feeling the actual object, such as the car radio’s tuning button, would give us more feedback, making the motion more precise.

Researchers at the University of Bristol’s Computer Science Department have developed a device that adds tactile sensation to a holographic image.

Co-developer of the technology, Sriram Subramanian, said it works on the same principle as the pressure of soundwaves you feel in your chest at a rock concert.

“Instead of using the bass sounds, what we use is low-frequency ultrasound - about 40 kHz - and that way we can target it at a precise point on your fingertip or on your palm, and then you feel the palm vibrate and it feels precise as well,” said Subramanian.

The soundwaves are emitted by an array of 64 small ultrasonic speakers, whose vibrations can be adjusted to create sensation of various shapes, and even their virtual movement.

Subramanian said the speakers can create hundreds of ultrasound focal points.

“And when I do hundreds at a time and put a hundred focal points around your fingertip or around your palm, those hundred feel like a circle," he said. "And if I track your palm and move them up and down, and if I change the diameter of these focal points, you start feeling like you are going through a sphere. And this is how we generate shapes.”

Subramanian said when it is fully developed, the so-called haptic technology may find application in various fields, from consumer electronics and home appliances to hospital operating rooms.