[Mr. Kim] and [John Sarik] made a presentation(pdf) at last weekend’s Botacon conference on how they made organic field-effect transistors (OFETs). A wooden RepRap, the fancifully named Unicorn from Makerbot (or printed from Thingiverse), hacked felt pen, a handful of chemicals, and a couple of pieces of lab equipment were needed to print (plot) out [...]