Imagine reaching out and physically shaking someone's holographic hand when you're Skyping them for the first time. Or how about giving a hologram version of a friend you're chatting with a hug while you're in two different countries?
Haptics researchers from the University of Tokyo's Department of Complexity Science and Engineering (DCSE) are aiming to make this a reality.
They've invented "Haptoclone," an interactive system that allows for an experience they've dubbed "telehaptics." With Haptoclone in its current form, you can send a holographic image of, say, your hand from one box to another box in front of another person. The cool thing is that Haptoclone also lets the other person experience the illusion of touching your holographic hand in their box.
"It would be great to allow people in different locations to communicate with one another while experiencing a sense of touch. We could, for example, put a transparent glass here and divide the room," explained researcher Yasutoshi Makino, gesturing at the point where the two components making up the Haptoclone device meet. "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."
The researchers presented their idea earlier this year at SIGGRAPH 2015, an international conference on computer graphics and emerging technologies.
The Haptoclone looks like something Houdini would use if he were still alive. It's composed of two box-like contraptions, each lined with four ultrasound arrays that emit ultrasonic radiation pressure (this is what gives the impression of touch when your hand passes over the arrays to "feel" something that isn't actually there). A Kinect sensor in one box captures a moving object's motions in real-time and the ultrasound arrays in the other box respond so you can "feel" it in the same position. Meanwhile special "aerial imaging panels," which act like a kind of mirror, make the object appear visually in the other box too.
For example, when Makino poked his hand into the hollow of the box on the right, a panel reflected the image into the space behind the box. A second panel helped produce a hologram version of his hand in the left hand box. When I reached out to touch Makino's holographic hand, I felt strange bubble-like sensations bursting up against my fingertips from the ultrasound arrays.
As cool as it sounds, the researchers admitted that for the moment people can only lightly stroke a hologram hand or object. The prospect of clutching someone's projected hand in a firm handshake or bear-hugging a person are still hypothetical, as they can't increase the ultrasound levels.
"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," explained Hiroyuki Shinoda, a professor at University of Tokyo with years of haptics research under his belt. "We have to consider the limitations."
The researchers have also had to deal with other challenges. Even though they had the idea several years back, they weren't able to easily realise it until they came across aerial imaging panels made by Japanese design firm Asukanet. At the moment, the panels are so expensive they're largely only used in research laboratories in Japan.
In order to make long-distance hapto-optical communications a possibility, the researchers will have to replace these panels with cameras that can reproduce the same effect over larger distances. That's something they're thinking of tackling next.
"Ultimately, we want to continue clarifying the function of haptic sensations to enhance and enrich human communications," said Shinoda.
"The images are so realistic, so it would be great to correlate the sense of touch with that. I guess that would increase the realness of it all," added Yoshikazu Furuyama, another researcher on the team.
Cool Japan is a column about the quirky and serious happenings in the Japanese scientific, technological and cultural realms. It covers the unknown, the mainstream, and the otherwise interesting developments in Japan.