A $.02 Ball Zinger
I haven’t tried a zinger and didn’t want to invest in the suggested materials, so I pondered some alternatives. What common, cheap things are sources of zinc and copper?
Eureka! U.S. pennies.
Pre-1982 they were 95% copper and 5% zinc (with some tin in the earlier years). There’s your copper.
Newer pennies are 97.5% zinc and 2.5% copper. Bingo, there’s your zinc.
File or sand the copper coating off the zinc penny and sand any oxidation off the copper one. You could use a new copper-coated penny in place of the old one if it is clean enough. The plating is enough to work. For long use, the old, 95% copper penny would be preferable because it can be sanded for cleaning.
Attach however you like. It could be to the underside of one of those wrist straps that are popular, a homemade thing, whatever. Use your imagination. You could even drill holes in the pennies and sew or tie them to your strap or ring.
Several could be used on each side for better contact. I haven’t gotten that far yet, having sanded the skin off the edge of my thumb doing the first one. Be careful.
I set the coins on my semi-sweaty leg about 2” apart and got a reading of .74v. The copper-coated penny produced the same voltage as the 95% copper.
As a test, I taped them to the sides of my even sweatier scrotum and got .51v. I’m not sure why this is lower. My balls are hanging loose and low, so maybe the contact wasn’t as good.
I know some are going to ask about the purity of the metals in pennies. Have you ever worn Levi’s without underwear? What about the purity of those copper rivets? Oh no. Do you wear a watch with a metal band? How about a necklace or an ear ring? What is in those? IMO, as long as there aren’t large amounts of nasty stuff in whatever sets against your skin, don’t worry about it.