Surfaces are bursting beyond their role as vehicles of architectural expression for a new life as powerful, mutating, interactive modifiers of our environment.

For the last time, I'm writing this column on my Macintosh G4 titanium laptop. When it came into my life a couple of years ago, it was the right sort of arm candy to be seen with in fashionable places. But it's now scratched and scuffed from hard use, and the surface coating has chipped off at the corners. Faithless as an ageing rock star, I'm about to dump it for the latest, perkiest, most radiantly unblemished newcomer - this time in brushed aluminum alloy.

Apple's choice of 'natural' metal surfaces for its new PowerBooks is a consumer electronics reprise of a characteristic late modernist, Herzog & de Meuron theme - the dramatic, beautifully rendered revelation of traditional material properties and fabrication effects in contexts where we have learned to expect paint, plastics and other elaborately synthetic industrial products. Yet the most innovative materials research is suggesting a radically different direction - that of adventurously exploiting microfabrication techniques and nanotechnology to provide thin surface layers with surprising new functions.

It's a story that began in 1959 with a lecture entitled 'There's Plenty of Room at the Bottom', by Richard Feynman. In it, he proposed the atom-by-atom construction of structures and devices with key dimensions measured in billionths of a metre and suggested some sensational uses, such as tiny, robotic heart surgeons that worked from the inside of blood vessels like tunnel repair workers. In the decades since, researchers have converged on Feynman's vision from two directions. From the top down, technologies for fabrication of computer chips and MEMS (microelectromechanical systems) have achieved finer and finer resolution, and are heading for nanoscale.

From the bottom up, chemists, materials scientists and guys with lasers and scanning tunnelling microscopes have learned to synthesise buckyballs (buckminsterfullerine, clusters of carbon atoms arranged in hollow spheres instead of graphite's sliding sheets), carbon nanotubes and other potentially useful nanostructures. Today, venture capitalists are reading business plans for nanotechnology start-ups and self-replicating goo is replacing modernist concrete in Prince Charles' nightmares.

For architects, nanostructures and nanodevices become particularly interesting when you embed lots of them in a substrate, like particles of pigment in layers of paint. You can engineer them to perform complex functions, making the surfaces of buildings do things they could never do before.

Self-cleaning, for example. Instead of scrubbing surfaces from the outside, you can provide armies of nanoscale automatic cleaners that do it from the inside. These can take the form of titanium dioxide particles. When pieces of nasty organic stuff encounter them, in the presence of ultraviolet light, a photocatalytic reaction takes place, and the bonds holding the organic molecules together break down. The guck simply falls apart and gets washed away in the next rain.

Particles of electronic ink, such as those supplied by E Ink of Cambridge, Massachusetts, are even more interesting. These are microcapsules filled with a mixture of positively charged white particles and negatively charged black particles suspended in a clear fluid. A negative electric field pulls the white particles to the top, and a positive field has the reverse effect. Electronic ink of this sort can be printed on to just about any kind of surface and controlled by integrated circuitry to create dynamic displays - video on paper, ceramics, cloth, and plastics. As it becomes more robust and capable, and as its cost drops, it will enable animated murals and wallpaper. Signage will become integral and continuous with the surface on which it is mounted, and will lie dormant and invisible until it is electronically activated.

Technologies for varying the transparency of glass have been around for a while, but the design possibilities expand excitingly when miniaturised electronic components add the possibility of fine-grained control. Imagine, for example, a frit pattern that can appear, disappear, and vary in scale and opacity. And stained glass is now being reinvented. In a system under development by Carlo Ratti at the MIT Media Laboratory, tiny squares of transparency-varying film become pixels in window-sized see-through displays.

Textiles, too, are becoming programmable. In other Media Laboratory projects, woven and embroidered fabrics contain smart thread structures that can serve as sensors, mechanical actuators that shorten and lengthen, and colour-varying lines, patches, or pixel arrays. One project is exploring the possibility of couches with memories; when you sit on them, you leave visible traces that slowly fade away. The fabric surfaces thus present themselves as continually transforming overlays of digital shadows.

Some of the most dramatic developments are in lighting. Increasingly tiny and efficient solid-state devices - particularly LEDs, light-emitting diodes - are challenging the glass spheres and tubes we have known for so long. LEDs can vary their intensities and colours. They can readily be embedded in strips of tape or arrayed on opaque, transparent, or optically variable substrates to provide a huge variety of effects. Lighting is becoming a function of surfaces rather than of discrete fixtures, and the difference between lighting and information display systems is vanishing.

The miracle material of the future will be a complex, fine-grained composite.

It will consist of a substrate providing electrical power and digital networking, with specialised, embedded particles that provide sensing capability, processing power, communication, mechanical actuation and controlled variation in optical, thermal and acoustic properties. It will suck into the wallboard many of the functions of lights, televisions and computer monitors, communication devices, cleaning systems, thermostats and interior climate control systems.

Document RIBAJO0020031223e01100009