Imagine ordering your meal in a restaurant by a simple tap on the table, transmitting your choice direct to the kitchens. Or placing an order for goods by making your selection on the surface of the shop window. It may sound like science fiction, but this could be the way we interact with computers in the future, thanks to a pan-European research project, led by experts at Cardiff University, Wales, UK. "The vast majority of us communicate with our computers using tangible interfaces such as the keyboard, mouse, games console or touch screen," said Dr Ming Yang of the University's multi-award-winning Manufacturing Engineering Centre (MEC), which is a Welsh Development Agency centre of excellence. "Although these are in common usage they have certain disadvantages - we are required to be 'within reach' of the computer and most devices lack robustness (to heat, pressure, water) restricting their spheres of application. Although some voice activated and vision systems for interacting with computers do exist, they are as yet unreliable." The vision of this new research project is to develop Tangible Acoustic Interfaces for Computer Human Interactions (TAI-CHI). It will explore how physical objects such as walls, windows and table tops, can in effect become giant 3D touch screens, acting as an interface between any computer and its user. The whole project is based on the principle that interacting with any physical object produces acoustic waves both within the object and on its surface. By visualising and characterising such acoustic patterns and how they react when touched or moved, a new medium for communication with computers and the cyber-world can be developed. While acoustic sensing techniques have been used for many years in both military and industrial applications, none is suitable for the multimedia applications envisaged by Tai-Chi. Some commercial products also exist, but are limited in their application to flat glass surfaces only and are restricted by size. The Tai-Chi project will go well beyond these limitations. "Our goal is to make this technology accessible to all," said Dr Yang, who leads the Tai-Chi team at the MEC. "Once that is done, the possibilities of application are endless." The Tai-Chi research project, supported by EC funding from the Sixth Framework Programme (FP6), sees the MEC co-ordinating the work with partners from Paris in France, Genoa and Milan in Italy, IMW in Clausthal, Germany, Lausanne in Switzerland and the University of Birmingham in the UK.