Many of you have heard about my main PhD project looking at tissue engineering of the breast through biodegradeable scaffolds. More specifically, I’m looking at the desired lattice structure of these scaffolds. Recently I’ve taken up another side project looking at a similar lattice principle for bone scaffolds. In difference to breast scaffolds, these need to be strong rather than flexible. They also need to have high porosity to encourage growth and regeneration.

This new side project is examining mathematically generated Triply Periodic Minimal Surface (TPMS) lattices for use within bone scaffolds. What makes TPMS mega sweet for tissue engineering is the way that you can maximise surface area while controlling porosity mathematically. Here’s a few below with their corresponding mathematical formulas:

**Schwarz G**

if((x^2+y^2+z^2<35),2-(cos(x+(1+sqrt(5))/2*y)+cos(x-(1+sqrt(5))/2*y)+cos(y+(1+sqrt(5))/2*z)+cos(y-(1+sqrt(5))/2*z)+cos(z-(1+sqrt(5))/2*x)+cos(z+(1+sqrt(5))/2*x)),1)

**Icosahedron**

cos(x)+cos(y)+cos(z)

I’ll be undertaking a number of tests with both acetone bathed and non-acetone bathed models. These include compression testing (with giant crushing machines) torsion testing (twisting stress) as well as Scanning Electron Microscopy and Micro Cat Scanning. I’ve got 44 different TPMS models to test, and to make things statistically significant I need to crush/twist at least 8 of each sample and MicroCT and SEM at least 3 of each sample.

This means…

Non-coated for Compression tests: 8

Coated for Compression tests: 8

Non-coated for Torsion tests: 8

Coated for Torsion tests: 8

Non-coated for MicroCT: 3

Coated for MicroCT: 3

Non-coated for SEM: 3

Coated for SEM : 3

44 x Models = **1936 Models Total**

*Sweet mother of Reprap*.

That’s quite a lot.

I have two 3D printers I can use at QUT for this, and can print about 14 models per day if all goes well. This means I’ll need 138 days of printing, or 5 months. This time will go down to about three months if and when the third QUT printer is repaired. The lengths of large scale studies for good scientific journals!

If you have a printer lying around which could be used to print scaffolds in down time, I would love to hear from you. I can supply the quality natural ABS plastic in 3mm or 1.75mm.

To say thanks, I will:

- Attribute you in the acknowledgements of the scientific article
- Give you an energetic high five
- Shout you dinner on a Tuesday night

If you could print me 44 or more, I’d:

- Paint you a watercolour portrait of yourself/Spock/whoever, or
- Shout you a case or a bottle of something

*‘Do it for Science’* - Carl Sagan