Project Facade: About

• Bioactive© glass facial implants
• Computerised Tomography (CT)
• Investrite
• Lost wax casting
• Magnetic Resonance Imaging (MRI)
• Stereoscopic Lithography and Rapid Prototyping

The material Bioactive glass was invented by American Professor Larry Hench during the Vietnam War. Tasked by the US Government to develop a material which could be used to repair large bone injuries suffered by Servicemen during the war, Professor Hench used silica (glass) as a carried or host material which could be combined with other ingredients such as calcium in a powdered form to pack between bone fragments to fuse shattered bones.

A technique of using ultrasound, gamma rays or X-rays to produce a focused image of the structures across a certain depth within the body, while blurring details at other depths.

Investrite is a castable material similar to plaster and is usually used by jewellers and glass casters. It is relatively soft once cast, making it very easy to remove when used to cast metal or glass using the lost wax process and counters plasters tendency to crack when exposed to heat. If used on its own it should be used within a specialist vacuum chamber. Lost wax moulds made by Paddy Hartley and Dr Ian Thompson are made using various ratios of plaster, Investrite and high temperature aggregate (the latter being crushed fire brick is used as a strengthening material).

Depending on the final form of an object and the type of metal or glass to be cast, the lost wax casting process has numerous variations and refinements. In its simplest form, a wax model of the object to be cast is produced and is invested in a mould that is usually made of a plaster type mix. Depending on the material to be cast, this mix recipe will differ. A wax extension is left protruding from the top of the mould, usually in the form of an upturned cone shape. The whole mould is then turned upside down and placed in a burn-out kiln where the mould is heated until the wax model inside melts and runs out of the extension and cone; hence the wax is ‘lost’. Whilst still hot, the mould is removed from the kiln, packed in wet sand (in case the mould cracks) and the molten metal or glass is poured into the cavity left by the wax via the cone and extension cavity in the top of the mould. Once the molten material has cooled, the mould is smashed from the cast at which point the sculpture can be cleaned and dressed as required.

An imaging technique used in diagnosing certain diseases. Using electromagnetic radiation, images can be obtained of the internal soft tissues such as the brain, spinal cord and other major organs. 

Stereoscopic Lithography and Rapid Prototyping are types of model production using three-dimensional imaging technology and three-dimensional printing systems. An object is either designed as a 3D form in a computer or a real object is placed in a scanner that reads every surface of the object.