Making new materials with 3D printing – and testing them
Materials testing has always relied on load cells, but advances in materials technology will require an ever increasing degree of accuracy. A paper in Nature describes how “Materials discovery and optimization have been a frustratingly slow process”, but the team describe a new method for
“A high-throughput combinatorial printing method capable of fabricating materials with compositional gradients at microscale spatial resolution.”
Basically, the team used aerosols to mix materials together and create new, printed multi-materials. What makes their system different is that the mix can be varied “on the fly” (their words). This combination of:
“Top-down design freedom of additive manufacturing with bottom-up control over local material compositions promises the development of compositionally complex materials inaccessible via conventional manufacturing approaches.”
So, having created these new materials, the team needed to test them. Enter load cells to track the strain and displacement distributions.
“The force–displacement relation was recorded by uniaxial stretching of the specimen up to 50% strain at a rate of 0.1% s–1 via an Instron universal machine (model 5944) with a 50 N load cell. The specimen was mounted in a pair of tensile grips, leaving a gauge length of 8 mm.”
Origami materials
Another paper on a similar topic in Nature also caught our eye “Multimaterial 3D printed self-locking thick-panel origami metamaterials.” It turns out that in this context, it’s not paper that’s being folded but mechanical metamaterials which are defined by their geometry rather than what what are made of.
“Rigid-foldable origami or rigid origami is a subset of origami, where facets that are typically rigid panels rotate around predetermined hinges without any tension-bend deformation during continuous folding process.”
The crux of the problem is that origami structures created by standard fused deposition modeling (FDM) 3D printing are strong, but rigid and can’t be folded. Origami made with soft materials don’t have the load capacity. The team realised that:
“The capability of 3D printing soft and rigid materials into one structure is desired for fabricating thick-panel origami structures.”
Having created thick-panel origami 3D sheets and a 3D printed self-locking thick-panel origami structure, the team used an MTS machine with a 10 kN load cell to for the following tests:
- Uniaxial tensile experiments
- Cyclic compression test
- Quasi-static compression tests
Load cells in material testing
If you need accurate materials testing using load cells, contact us to discuss your requirements. Or check out our articles below:
A load off your mind: how to choose the right load cell for your materials testing
