Sensacell has announced the development of a new interactive floor to go in the entrance to Spains Comunitat Valenciana in time for the Water and Sustainable Development themed World Expo being held there this year.The floor is 250 square feet and contains 1000 Sensacell interactive modules and LED lighting, and is made of glass.People walking across the floor will leave behind luminous footprints on the floor to highlight the footprints made by the human race on the environment.The Expo will run until September 14th this year and the floor will be on show for the whole event.Other examples of sustainable energy on display will include walls of water. The walls, designed by architects at the Massachusetts Institute of Technology, put out water from thousands of jets which are computer controlled sensors, as reported on USA Today.If a person walks towards the walls the sensors can make the water flow around them, giving the effect of a door opening in the water, which will close when the person has walked through.