. (CNN)In 1971, a physicist conceptualized the existence of a fourth fundamental element in the electronic circuit, besides the three that were already in use at the time.

His name was Leon Chua and he believed -- for reasons of symmetry -- that an extra component could one day be constructed to join the resistor, the capacitor and the inductor.
He called it "memristor", a portmanteau of the words memory and resistor.....

http://www.cnn.com/2015/02/26/tech/mci-eth-memristor/