nomad

Here is a basic one https://www.youtube.com/watch?v=q32Fr0Hh84o

His earlier videos are all about conductive ink

Look for the channel of Robert Murray-Smith. He has tons of videos on diy conductive ink.

I guess your best bet is Pollin. Other than that aliexpress or eBay.

Hackers

I’m a software dev, but I also do all the design architecture and infrastructure work. I like that there are new problems to aolve every day so it doesnt get so boring.

There is nothing about insect repelling qualities for the tree itself in the article you linked.