Scientists in Japan have created the first 'touchable' hologram, enabling users to experience the illusion of touching objects that aren't really there.

The Haptoclone, created by haptic researchers from the University of Tokyo's Department of Complexity Science and Engineering, consists of two boxes, one containing an object and the other displaying a hologram of it.

When a human hand comes into "contact" with the 3D image in the second box, the hologram emits ultrasonic radiation pressure, making the user feel they are actually touching the object. Meanwhile, special aerial imaging panels act like a kind of mirror, making a hologram of the hand appear visually in the other box, too, so it can "interact" with the original object.

The technology seems remarkably realistic – a Gizmodo reporter said she could tell that the holographic ball she was interacting with was made of inflated plastic just by "touching" it.

For the moment, Haptoclone is limited due to it only being able to emit safe levels of radiation, meaning the tactile sensations are reduced to a light stroking rather than a handshake or a hug.

"The [level] of ultrasound we're currently using is very safe, but if it's too strong, ultrasound can damage the insides of the human body, such as the nerves and other tissues," Hiroyuki Shinoda, a professor at the university, told Motherboard. "We have to consider the limitations."

Scientists believe the next step will be to increase the use of the technology across all forms of communication, allowing users to give virtual hugs, handshakes and high fives through the internet.

"It would be great to allow people in different locations to communicate with one another while experiencing a sense of touch. Imagine if you were in a zoo and there was a lion on the other side of the glass that you could have the sensation of touching," said researcher Yasutoshi Makino.