Origami Cordyceps

Cordyceps is a type of fungi that infect living insect, control it, and eventually make the insect move to desirable place to die. Then the fungi will release its spore to complete its life cycle.

Background

After learning about this organism, I thought it will be cool to design an insect with fungi protrunding from its body. Ant is a good candidate for the insect, given its simplicity. As for the fungi, cordyceps doesn't have interesting structure. It is just like a brown appendage sticking out of the insect. Because of this I decided to go with the typical edible mushroom. Deviates from the realism, but delivers the message!

The sketch will be something like:

Design

The ant should be straightforward. As for the fungi, we can use a single long middle flap and sink the tip. The sunk part can be spread, exposing a flat top as shown in picture below. In reality the flap needs to be narrowed down too. I have seen similar structure being used in Tetsuya Gotani's catfish, as well as Robert J. Lang's red throated hummingbird and lobster. All used for fan-like structure for the animal's tail.

To achieve that, I need a flap which is much longer than any of the ant's part. This property is hard to achieve using tiling method (assembling molecules, or 22.5 degree method). Circle packing could be used, but I imagined filling the molecules may be tricky when there is a large difference in circle sizes. The most suitable method I thought would be box pleating, which ensured the flap's width is constant regardless of its length (although it's thicker), and easy to compose.

To start, I put the long flap in the middle. Then one by one, add the body parts. I tried to make the legs' thickness uniform, so all of them are made using edge flap. For the head, I was able to make antennae and mandibles. A 24 x 24 grid is enough for this arrangement.

Fold

Test fold on A4 paper shows good result. I proceed to try a different paper other than the craft paper used in previous models, partly due to difficulty in shaping the fungi. I used single tissue which I recently learned to make, with 25 cm x 25 cm size.

As promised by the paper, it is able to keep its shape once it dries. However the final model is quite small, it is only 0.2x of the original paper size. I should have used larger paper, to thin the legs even more and to make more accurate folds.

Anyway, this is the first time I can make an explicitly segmented leg in an insect model, since usually the paper got too thick and unpleatable.