Excerpted from Vasilis Kostakis and Marios Papachristou:
“For Gershenfeld (2012), Lego exemplifies the digitization of material celebrating modular design, while conventional 3D printing represents just an analogue process, which often accumulates errors, based on digital files.
‘In comparison to traditional (analog) 3D printing in which material is deposited or solidified in an inherent continuum’, Hiller and Lipson state (2009:137), the digitization of material imposes finite resolution: ‘the size of a single unit’.
Therefore, Gershenfeld (2007, 2012) proposes a different approach to 3D printing, viewing fabrication as a digital rather than a continuous process. An adjunct to the idea of 3D printing is investigated and tested based on the concept of ‘‘voxel’’ (Hiller and Lipson, 2009; Hiller et al., 2011; Lipson and Kurman, 2013). According to Lipson and Kurman (2013: 16):
– A voxel is the physical equivalent of a pixel. Voxels could be tiny, discrete pieces of a solid material. Or voxels could be tiny containers that hold whatever you put into them. (. . .) Objects made of voxels offer an alternative to the analog materials that comprise most physical things. If you can make something from voxels, you’re one step closer to making it behave more like a programmable object, to controlling its behavior. Control over material composition of physical objects opens the door to the next stage, control over the behavior of physical objects. Hence, any object (module) that has modularity and repeatability in its use to render a larger unit can be considered a voxel. The modularity enabled by voxels can help us create objects with completely different material properties such as strength, flexibility and/or functionality (Hiller and Lipson, 2009).
‘The key to scaling up the complexity of microsystems’, Hiller, Miller, and Lipson write (2011: 1094), ‘lies in modularizing material and function, which requires standardizing the interface between components’. So, this way the fabrication of each module type can successfully take place in independent optimized processes and then combined into a functional hybrid system (Hiller et al., 2011). ‘This enables materials and functions that would otherwise be mutually incompatible to be combined in a single integrated system’, Hiller, Miller, and Lipson (2011: 1094) conclude. A standardized library of voxels with compatible geometry is envisioned, which will be manufactured in several different ways, depending on the geometry, material and size (Hiller and Lipson, 2009; Hiller et al., 2011). However, it may be most economical to mass produce the voxels since the voxel manufacturing techniques are highly specialized processes (Hiller and Lipson, 2009). Hiller and Lipson (2009) highlight that the idea of central manufacturing and distributed assembly is obvious in Lego products as modular structural components. They (2009: 147) speculate that ‘as long as the function of each voxel is elementary, there will be a finite (and likely small) number of voxel types required to build arbitrarily complex objects. The end-user would order voxels of many different materials and functions.’
To sum up, we see that the voxel-based approach introduces modularity in hardware components digitizing desktop manufacturing and arguably enhancing its capabilities. Through our case study we will try to show how it can assist individuals to engage in production processes of collaborative designing and manufacturing. According to all the bibliographical resources cited above, Lego represents a typical, illustrative case of the voxel-based approach to physical manufacturing. Of course, one of the biggest challenges of digital fabrication concerns the processing of large numbers of voxels fast and accurately (Hiller and Lipson, 2009; Lipson and Kurman, 2013). In that way, eventually, it will be possible to print conductors within nonconductors, or in other words to move from ‘printing passive single-material parts to printing active, multimaterial integrated systems’ (Lipson and Kurman, 2013:272). It is evident that since we will have the ability to print in voxel-based 3D printers physical things that contain the intelligence of digital things (Lipson and Kurman, 2013; Gershenfeld, 2007, 2012), the role of knowledge and design becomes even more important. And therefore, the conjunction of CBPP with digital fabrication arguably reaches a new plateau concerning the ability, in Gershenfeld’s words (2007, 2012), ‘to think global and produce local’.