During my time at the NRC-CNRC, I explored how to characterise the microstructure of a ceramic sample and understand why certain biological analogues were so much tougher than their synthetic counterparts. This 12-month research exploration, coupled with a fellowship experience at MIT, gave me a fascinating insight into the world of bio-inspired structures and our evolution of manufacturing technologies in order to mimic nature.
The Problem With Brittle Ceramics
Ceramics are a valuble class of materials — heat resistant, wear resistant, chemically inert. But their Achilles heel has always been brittleness. Under stress, a crack propagates almost instantaneously through the material with virtually no energy absorption. For aerospace and structural applications, this is a critical limitation.
Nature, of course, solved this problem millions of years ago. Nacre — the iridescent inner layer of mollusc shells — is made of 95% aragonite, an extremely brittle material. Yet nacre is 3,000 times tougher than the same aragonite in bulk. The secret is entirely architectural.
Reverse-Engineering the Microstructure
Using a CNN-based classification system I built with OpenCV and TensorFlow, I began systematically identifying and cataloguing the architectured design that distinguished high-toughness designs from low-toughness ones. The patterns that emerged were striking:
- Layered "brick-and-mortar" composite architectures that absorb impact energy & deflect crack propagation
- Stochastic (random) 6-sided tile structures which influenced the impact toughness
- Hierarchical structure operating across multiple length scales simultaneously
The insight wasn't that these features existed — researchers had known about them for decades. The insight was that they could all be produced through deliberate process design. Laser intensity, focal position, ceramic opacity, power — each manufacturing variable corresponded to a specific microstructural outcome.
From Observation to Process
I worked backwards from the target microstructure to the process conditions required to produce it. The result was a bio-inspired ceramic manufacturing process that achieved a 220% increase in toughness compared to conventionally processed samples of the same material. The findings were published in a few articles:
Google Scholar ProfileThis principle — that manufacturing process and material architecture are inseparable — has shaped my thinking on professional projects since. For example, qualifying new filaments for your 3D printer isn't just about what spool of plastic you're feeding into the system; it's about fundemendally understanding and mapping the relationship between print process parameters and the construction of the crystalline & amorphous microstructure that emerges from them.
What This Means for Additive Manufacturing
Additive manufacturing offers something no conventional process can match: the ability to programme microstructure spatially. Varying deposition parameters layer by layer, you can create deliberate gradients in crystallinity, porosity, and fibre orientation throughout a part's cross-section.
We're still in the early stages of exploiting this fully. Most industrial AM today treats the process as a near-net-shape fabrication tool and optimises for dimensional accuracy and surface finish. The next decade will be defined by those who learn to programme the microstructure itself — and the engineers who understand both the materials science and physics will have a significant head start.