Silicon Dioxide (aka Silica and Sand)

Sand is hardly a material that is on a designer’s radar. However it deserves a mention in this book due to two very different projects using it as a material from which new techniques of production have been born.

There is growing evidence to suggest that the future will be defined by new uses for old materials. An increasing number of inventors from design backgrounds have taken to scavenging the world of materials that are traditionally perceived more as substances than as materials. The bio-manufactured brick is a project developed in the deserts of the United Arab Emirates that uses bacteria combined with sand, salt and urea from animal urine (a common element in urea-formaldehyde plastics) to turn sand into a usable building element. Developed by Ginger Krieg Dosier of the American University of Sharjah, the process combines readily available ingredients to make a brick without the intense heat usually associated with making ceramics.

Another project that uses sand as a raw material is much more simple but no less inspiring. Developed by designer Markus Kayser, the SolarSinter project takes a machine powered exclusively by the sun and uses its energy to sinter – a process that uses heat to fuse fine particles together – sand into solid objects. Although this is a project more about a new manufacturing process rather than a material, it illustrates how designers are taking a lead in the search for alternative materials from which to make products.

Image: Better Brick project

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Key features

Excellent hardness

Non-conductive

High resistance to thermal shock

High temperature resistance - 1704ºC (3099ºF)

Sources

Silicon dioxide is one of the most common substances in the earth.

Cost

Impossible to define precisely.

Sustainability issues

Sand is widely available and the case studies mentioned here use low energy to form the materials.

Production

Markus Kayser’s sintering sand project takes the production of silicon dioxide into a whole new arena through its use of solar energy to fuse grains of sand. Another production method is based on a form of casting, where fibres of silica are suspended in water while being cast in a porous mould. As in slip casting, the water is drawn out leaving a dry, open-celled structure.

Typical applications

Silicone dioxide is the dominant ingredient in glass making, glazing for ceramics and in cement. It is also used for its temperature resistance in space shuttle tiles, where a lightweight 0.028 cubic metre (1 cubic foot) block weighs less than 4 kg (9 lb).

Derivatives

–Silica aerogel

–Glass

–Portland cement (around 24%)

–Silicon dioxide is found as quartz in granite

–Major ingredient in sandstone

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–Extremely hard

–High temperature and therma-shock resistance

–Widely available

–Manufacturing processes still being developed

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