Resin 3D printing could make rapid multiple-material printing a real possibility

3D printing multiple materialsWhenever a journalist sits down to pen one of those ‘Why 3D printing is not actually the future and you are stupid if you think it is’ –type articles, they invariably include a list of reasons why additive manufacturing is not suitable to widespread usage.

In matters of speed, cost effectiveness and reliability, they will claim, 3D printing cannot compete with traditional, subtractive manufacturing techniques.

The problem with these articles is that they seem to assume that 3D printing will never improve past its current state and, even if it does, improvements will only result in a stronger version of the current technology. Truly game changing developments, however, are far more  unpredictable than that and allow technology to evolve as oppose to simply strengthen.

3D printing multiple materials USC

One such innovation may well have been announced yesterday by researchers at the Viterbi School of Engineering in the University of Southern California. By developing upon a printing process created last year in order to speed up the rate at which objects can be printed, the team have come up with a way to create items comprised of multiple materials at a rapid rate.

The original technique, which boasted the snappy moniker Mask Image Projection Based Stereolithography (MIP-SL), took the traditional resin printer method and shifted it into top gear. Resin printing generally works by taking a pool of liquid resin and running a laser across it in layers, hardening it piece by piece until it takes the shape of the intended object.

With MIP-SL, however, the 3D digital model is sliced into a set of planes, which are in turn converted into 2D mask images. These images are then projected onto the resin. A light is applied that cures the resin into the shape of the related layer.

Without the need for the laser to make several, time consuming passes, this speeds up the process of 3D printing with ruthless effect. An object that once took three hours is now on the platform within minutes.


Now, the Viterbi School of Engineering team, lead by Professor Yong Chen, have taken the method a step further by applying it to the printing of objects that require more than one material. One of the key issues with printing multi-material objects is the fact that different materials will harden at different speeds. The USC Viterbi team have designed a programme that tells the printer where to makes its deposits and when.

Not only does this allow prints to be made using more than one material, but also it allows objects to have different structural consistency at different parts. In the video above, Chen uses the examples of a tweezers, where some parts need to be soft and some hard to give the device the required flexibility.

The next step for Chen and his team is to automate the process, making it possible for a wider audience of consumers and enthusiast to use the method. Forward steps like this one show that, rather than settling for its current limitations, 3D printing is slowly but surely developing beyond many of its key drawbacks, as it captures the imaginations of the world’s most innovative minds.

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