I have often wondered if it were possible to create a homemade diode -- out of nothing more than aluminum foil... I'm guessing (but not knowing!) that this cou

I have often wondered if it were possible to create a homemade diode -- out of nothing more than aluminum foil... I'm guessing (but not knowing!) that this could be done as follows: 1) Take two pieces of aluminum foil. 2) Roll one of them into a pyramid or cone of some sort... Whatever shape it is made into, it needs to taper to a sharp point at the end, much like a pyramid or cone... 3) Take the other piece of aluminum foil and coat it with an oxide layer. Basically burn it -- but don't melt it! 4) Now take the conic/pyramid shaped piece of foil and "point it" (for lack of a better term!) at the oxide layer on the other piece of foil, similar to a "cat's whisker" diode (https://en.wikipedia.org/wiki/Crystal_detector https://en.wikipedia.org/wiki/Crystal_detector , https://rimstar.org/science_electronics_projects/razor_blade_diode_for_crystal_foxhole_radio.htm https://rimstar.org/science_electronics_projects/razor_blade...) 5) Spacing (pressure) is very important! If the point is a micrometer too close or too far away -- it might not work! The casual observer would think that a "cat's whisker" diode has a direct connection between the surfaces -- but I would think that there's at least a little bit of capacitance (space) there -- determined by the pressure! So, would it work? ? I don't know! I don't currently have a multimeter to test the idea! But, I think it would be tremendously interesting if someone could create a working semiconductor (in this case a diode!) out of easy-to-find household items! (Yes, I know the "cat's whisker" works -- but I'm talking about still other items -- the reason for this is to understand semiconductors better -- in other words, there's more to the "P-N junction" theory than is taught -- since early diodes (tubes and other devices) DID NOT use doped semiconductors to obtain this electrical effect!) So, the thread submitted above, on the Raspberry Pi forums -- is about some other ways to make diodes... Anybody have any other ideas on how to make semiconductors using non-traditional semiconductor materials? ?