[pjc50]

Graphite counts; if you want to manufacture it from forest materials, compressed bonded charcoal might work. https://www.sciencedirect.com/science/article/abs/pii/S01675...

[agumonkey]

True but its resistance might be too high maybe ? also it's not easy to make graphite.

Thanks a lot for the link though. Are you into green electronics by any means ?