While touch screens have existed for decades, multi-touch screens are still a relatively new innovation. That's the kind of screen found in the iPhone, iPad and other devices. It allows the user to touch the screen at three or more points, and enables stretching, dragging and other kinds of digital manipulation.

While multi-touch screens are becoming more and more commonplace, German researchers are now working on integrating this same technology into floors. Users would interact with the multi-touch floor by using their feet.

"When I walk across the floor with my shoes, I get a glowing, infrared imprint of my footprints," explained Patrick Baudisch, head of the Human Computer Interaction group at the Hasso Plattner Institute in Potsdam, Germany.

"And from that we can reconstruct where people are, and what shoes people wear because the soles are recognizable."

The demonstration model of the "Multitoe" floor is about the size of a coffee table and measures about one meter by a half meter, and is raised up off the ground. The floor itself is made of a thick piece of glass, topped with a black sheet of acrylic. A camera, built-in to the floor, points up towards the ceiling.

The research team uses a technique called frustrated total internal reflection, that had been developed for use in finger-print scanners, until Jeff Han from New York University adapted it for use in multi-touch displays.

Baudisch and his team hope that a multi-touch floor could be useful as a new way to interact with large amounts of visual data - like maps - or to play video games.

Logging into the floor

One of the interesting things about the floor is that you can log into it, just like a computer, because it can recognize individuals based on the pattern of their shoes.

When Thomas Augsten, one of the students working on the project, steps up onto the multi-touch floor, floor asks him a question: who are you?

Augsten taps the word "new" for new user, the floor scans his shoes and he's given a color. A keypad then appears on the floor and Augsten types in his name with the toe of his shoe, making him a registered user.

While it is possible to type standing on one foot, it would probably be too tiring to write more than a few words.

One of the first challenges the research team had to overcome was how not to interact with the multi-touch floor - it has to be able to differentiate between people just walking around, and understand when they want to interact.

A smart floor could show the way

According to Johannes Schoening, from the German Research Centre for Artificial Intelligence in Saarbruecken, a touch sensitive floor could open up a whole range of possibilities.

"The main advantage is you can sense what's going on, on the floor," he said "But now you have to think about so what can you do with that information. So for example if you are in the supermarket, you can provide navigational instructions."

Other examples could include a smart-floor in a museum or an airport that shows you the way - or even a dance club where you can interact with the visuals on the floor.

Previously, the Sustainable Dance Club company in the Netherlands created a floor that generates power when people walk, jump and dance on it. It's fitted with LED lights that can change color, but these use as little energy as possible because generating power is the priority.

Eric van Duin, an engineer with Sustainable Dance Club, said his company is excited about the potential of an interactive floor like the Multitoe - just as long as it doesn't use too much power.

"Our touch experience is very limited, so maybe it would be very interesting to combine these technologies to enhance our dance floor", he said.

Not just entertainment

Because the Multitoe floor has a pressure sensor, Baudisch added that potentially it could also be used as a medical tool to analyse posture and assess back problems, or in an assisted living situation. The floor could sense if people have fallen down and help to increase the safety of inhabitants - without the drawback of visual surveillance.

"We probably wouldn't like the idea of people installing cameras in our homes," he said.

"And so you could envision something like a touch-sensitive floor that could actually reconstruct bits of your day. Have you gotten up? Have you gotten some exercise? Have you dressed? We can reconstruct a lot of these things, but without a lot of the privacy implications that a whole camera system has."

A future of touch-screen interactivity

Even so, researchers envision a future where multi-touch devices and interactive elements like walls and floors could become a part of our everyday lives - where visual data will migrate between different devices - from an iPhone, to a table, or be spread out and manipulated on a multi-touch floor.

Still thought, despite the current boom in multi-touch devices, Schoening also cautioned that modern society shouldn't incorporate multi-touch technology into everything just because it's sexy. He added that designers and application developers should also think about where multi-touch devices are actually needed.

"There are definitely some really crappy examples how we should not use multi-touch," he said. "Do we really need a multi-touch iPod nano when all the thing we can do is rotate the mainscreen?"

Author: Cinnamon Nippard
Editor: Cyrus Farivar