New Scientist: Putting the touch into touch screens

As neuroscientists decode how we process signals from nerves that sense touch, engineers are beginning to use their discoveries to dupe us into feeling something that isn't there. Given the right kind of manipulation, a smooth surface can be made to mimic the feel of a range of materials, and a solid slab can be made to feel like shifting sand… It is not just the sense of touch in our fingers that is attracting the attention of haptics researchers. Instead, Yon Visell at the Centre for Intelligent Machines at McGill University in Montreal, Canada, is focusing on the feet, and has developed a novel surface designed to simulate walking on different types of ground. It uses a series of 30-centimetre tiles, each with sensors at its corners and an actuator similar to a loudspeaker coil mounted beneath it. By modelling the properties of various surfaces and calculating what vibrating forces the coil should apply as different parts of the foot make contact with it, Visell has been able to mimic the sensation of walking on solid ground, gravel or sand.