Riccardo Tonello: Increased precision in 3D printing enables new types of innovative surfaces in appearance that extend the variety of applications.
The always increasing demand of more and more complex materials in both texture, shape quality and appearance, generates a demand for an improvement of 3D technology and 3D printing in particular. In fact, 3D printing includes a very wide range of technologies and applications but there are still some limits (e.g. printing time related to printing precision) that makes it not applicable under certain condi-tions and for some fields.
In this context, appearance and texture are two hard topic for 3D printing, since it is not possible to reach particular effects or high precisions in short times. Overcoming such limits and improving the technology, is very important in order to design advanced surfaces which could cover an additional slice of applications meeting the different needs of the market and even be fundamental break-throughs, such as innovative panels for the aerospace field or artificial organs for the biomedical one.
Digital Light Processing (DLP) 3D printing is one of best technologies in terms of precision and print time and it can act in this sense, but it still suffers, in its turn, from some limitations and defects (e.g. ‘staircase’ artefacts due to the layered printing) even if they are not directly visible.
A DLP printer consists in a vat of photo-reactive liquid resin that is selectively exposed to light in order to form very thin solid layers that stack up to create one solid object. A digital light projector flashes a single image of each layer across the entire platform at once. Because the projector is a digital, the image of each layer is composed of square pixels, resulting in a layer formed from small rectangular bricks called voxels.
Combining material reflectance, optics, and industrial post-print surface, the aim of the project is creat-ing a continuous print method which outperforms the conventional layer-by-layer method by eliminat-ing the discretization artefacts.
We thus propose research with focus on producing smoother or optically innovative objects faster.
Figure: Hemispheres and bunnies with smooth and rough surfaces, and flat samples (smileys and QR code) with spatially varying anisotropic reflectance. The scene is observed from two different di-rections to exhibit the anisotropy. The sun is used as a directional light source. Each item was print-ed in a one-step process using the presented technique.