The following images and text are from a recent installation at the Royal College of Art as part of the Inspiring Matter 2012 conference on materials, art and innovation:
Nylon-Silicone Composites placed in tension
Additive Manufacturing is unique in that the complexity of an objects form has little to no bearing on the cost or time it takes to produce it.
Despite this benefit, the impact of Additive Manufacturing on commercial products has been limited. The outputs, though visually convincing, have often failed to provide the mechanical properties or aesthetic qualities we take for granted in everyday products. The few examples that have managed to use these processes effectively have all focused on the creation of niche artisan objects: ornamentation, jewellery and accessories — where the complexity of forms and negligible setup cost allow for short runs of aesthetically unique objects.
But is there more we can do with this powerful means of rendering complex form? Just how far can Additive Manufacturing by pushed?
Variable Density Auxetic Sphere
Printing Hybrid Materials —
As these technologies have developed, one of the major performance parameters has been improving resolution. Most machines now create layers at the scale of microns. Selective Laser Sintering is one method that can manufacture at below the millimetre. Its unique approach of fusing powder particles allows the creation of robust elements with thicknesses as fine as 0.4mm.
At these resolutions we are able to fabricate structures with details at the boundary of our perception. When we assemble these sub millimetre elements into a lattice we create a plastic foam – a hybrid material of nylon and air. Similarly we can embed these structures into other materials such as silicone to form composites. The physical and mechanical properties of these hybrid materials depend on the structures we impose. As such we design material through microstructural geometry.
Variable Density Auxetic Sphere (Macro)
From Selection to Design —
The implications of this leads us to larger questions. What does it mean to be able to design material in relation to products? How do we as designers explore and exploit these opportunities?
When we consider an object we have a tendency to split its form and its material such that we can deal with them one at a time. Doing so make the problem easier — after all material is but a parameter of form. Materials make a form hard or soft, strong or tough, they are in the context of an object, one dimensional.
Designing material offers us unprecedented control over their properties. We no longer have to select but can shape them to our exacting requirements. I can make them lighter, stronger, tougher but again how important is this? Not all our commercial products are solely performance driven. Is there more to this than simply property optimisation?
Nylon-Air Non Convential Auxetic Foam Block
What makes using additive manufacturing unique in the fabrication of hybrid materials is the level of control we are able to achieve. We prescribe every single strut, every joint, and every contour and as such we are able to change them not only en-mass but also at a local level. We are able to vary our microstructures, changing them as we please and as a result creating variations in properties throughout an object volume. We move from one material to another simply through microstructure.
In doing so we elevate material. A material is not solely soft or hard, it can be soft to hard or vice versa (the precise description is a function of its form). Suddenly the way an object behaves in three dimensions is not solely prescribed through form, but also through material. Perhaps an apt example is in a loaded die. The intention in such an object is to favour a certain behaviour — we wish to make it more likely to land on one particular face. Changing the shape of the dice from a cube is not an option; it makes the deception obvious and defeats the objects purpose. However by changing the distribution of weight — varying the material within the form — we can embed this behaviour into the object.
Designing material then offers us more than just better properties. It adds a new dimension in prescribing behaviours on the artificial. Embedding behaviours through microstructures not only challenges our visual understanding of form but also enables us to embed a new level of sensory and functional intelligence into material, which we control.
Nylon-Air Non Convential Auxetic Foam Block (Macro)