Here's a thought: RAM.it works by
if there's a current, then 1 else 0. What if it could detect voltage?
if volt > 21v then 001,
else if volt > 18v then 010,
else if volt > 15v then 011,
else if volt > 12v then 100,
else if volt > 9v then 101,
else if volt > 6v then 110,
else if volt > 3v then 111,
else 000.
each cell could hold 3 bits of information apposed to just 1...