'Hand-made' pills inspired by a starfish (Day 153)

'Hand-made' pills inspired by a starfish (Day 153)

27th October 2014

I've blogged a few times over the past five months about 3D printing. It's one of those technological developments which has attracted the attention of chemical engineers, despite some apparent anomalies.

Our profession spends much of its time producing items on a massive scale. We deal in huge volumes which provide food, energy, water and healthcare to hundreds of millions of people.

By contrast, 3D-printing operates in small numbers - even ones and twos. In fact, I think 3D-printing is synonymous with the phrase 'hand-made' - unique, custom-designed, high quality and carefully crafted. Who knows, 3D printing may herald the end of some traditional skills.

Echinoderm sea creatures such as brittle stars have ordered rounded structures on their bodies that work as lenses to gather light into their rudimentary eyes. Under the microscope, the shell looks like little hot air balloons that are rising from the surface.

mimicking the shells could potentially be useful to guide light in advanced LEDs, solar cells and non-reflective surfaces.

But in a lab, crystals composed of the same minerals tend either to be faceted with flat faces and sharp angles, or smooth, but lacking molecular order.

University of Michigan engineering professors have made rounded crystals with no facets, a structure occasionally found in nature but difficult to produce in a lab. Image credit: Max Shtein

The nanoscale shapes are made out of boron subphthalocyanine chloride, a material often used in organic solar cells.

It's in a family of small molecular compounds that tend to make either flat films or faceted crystals with sharp edges, according to Max Shtein, associate professor of materials science and engineering and chemical engineering [as well as other roles], at the University of Michigan.

Max says: "I've never seen shapes that looked like these. They're reminiscent of what you get from biological processes.

"Nature can sometimes produce crystals that are smooth, but engineers haven't been able to do it reliably."

The process used to manufacture them—organic vapor jet printing—might also lend itself to 3D-printing medications that absorb better into the body and make personalised dosing possible.

The organic vapor jet printing process is a technique Max helped to develop. He describes it as spray painting, but with a gas rather than with a liquid.

It's cheaper and easier to do for certain applications than competing approaches that involve stencils or can only be done in a vacuum. Max is especially hopeful about the prospects for this technique to advance emerging 3D-printed pharmaceutical concepts.

According to Max and the team working on the project, the method offers a precise way to control the size and shape of the medicine particles, for easier absorption into the body. It could also allow drugs to be attached directly to other materials and it doesn't require solvents that might introduce impurities.

Good work and you can find out more about their research online.