Jim did some experimenting with homemade thin-film zinc oxide and zinc-tin oxide, developing his own homemade transistors devices -

I did manage to achieve (with a liquid dielectric) voltage and current gain, as well as construct a functional astable oscillator using two of the devices constructed on a single substrate. While the speed of the devices (due to the liquid dielectric) is such that they are only interesting as a technology experiment, they’ve been a lot of fun to experiment with.

Some very interesting work here. There’s really no better way to understand technology than to build it yourself. I can say firsthand, building a simple capacitor or LED from scratch is a lot of fun – a DIY transistor must feel like a straight-up triumph! Download the documentation of Jim’s experiments in PDF format on his site.

Related:

MAKE Presents: The LED – and how to make your own from carborundum!