This made me imagine an educational toy that allows you to make working simple circuits by drawing: You draw with markers that have electrically conductive ink, then touch the contacts of a 9-volt battery to your drawing at a certain point and a bulb or LED that you've taped to your drawing lights up. Maybe you'd supply prefabricated stickers that contain logic gates that you stick to the paper where you need a gate.
As the other comment mentions, this is a thing already, but thanks for bringing it up. I'd completely forgotten about it and it seems like a good hands-on way to get a better understanding of circuits.
