Leon Chua, a professor at UCal Berkeley, once theorized there should a circuit that remembers how much current flows through a device. According to Chua's theory scientific symmetry would seem to demand the existence of this complementary circuit to resistors, capacitors and inductors. Now, 37 years later scientists at Hewlett Packard are set to publish a paper demonstrating the existence of this type of circuit, called 'memristor' for memory resistor. If researchers can make these circuits commercially viable, it could lead to new high-density, low-energy types of memory. Memristors work due to its level of resistance changing when current is applied. Thus a high/low level of resistance can be interpreted as a 1/0 state, the basis of data storage. HP has been able to build both discrete memristors and memristors embedded in a silicon chip.