CPK Molecular Models with Polymer Clay

I’ve been getting into molecular modelling recently, and I wanted to experiment with different ways of making my own models cheaply and easily. I liked the colour scheme and layout of the CPK modelling made by Linus Pauling and others, but their models are fairly chunky, so I decided to go with half the scale they used (1 Angstrom now being 6.25mm)

This was my first idea, a 6mm deep template to mark out the right volume of clay for each atom type: thumb_IMG_2868_1024.jpg

Once you have the right amount of clay, a heavily scientific process known as ‘smushing’ is used to turn it into a sphere:


A perfect 1.7 Angstrom radius carbon atom. 

While that worked, it wasn’t terribly quick. After playing around a bit, I redesigned it to allow multiple atoms to be cut out at once. Also, the edges of the jig are used to support a rolling pin exactly 6mm from the surface, so the volume is nicely repeatable.


How you split an atom. 

Also note the different coloured markings on the edges, allowing you to divide up the clay for different atom sizes. I simplified it a bit down to only four sizes, since I figured people won’t be able to tell the different between a sphere of radius 1.52A and 1.55A just by holding it in their hand.

Once the atoms are divvied up, you can even put in some rare earth magnets to make a suitably geeky fridge magnet:


Astute readers will note that the clay making up these atoms, is actually made of atoms also, which I maintain makes this a fractal. 

You should really use a better work surface than MDF too, my clay got all grubby because I didn’t think to prepare something cleaner. A glass countertop is perfect to work on and easy to clean afterwards.

Then just bake the clay as normal in the oven:


Being cooked. Does that make this a reactor? 

Rather than my home oven which I’ve used previously, I used a turbo oven so I could bake them at the R+D space. Turns out the turbo oven I used either isn’t perfect for polymer clay, or I need to work on getting the airflow managed better. The models I made broke apart, but were easily superglued back together. I’m not concerned, the main thing I wanted to get sorted was the cutting jig, and I’m extremely happy with how that turned out.

While mushing clay atoms together isn’t going to give the world’s most precise atomic angles, it’s certainly capable of capturing the feel of a various compound, and I’d suggest it’s a good way to aid learning.

Files up here for anyone that wants to make their own:


And if you do make your own model, please let me know and I’d love to see a pic!


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