A memristor was a 2-terminal non-volatile memory device that was based on resistance switching effects. When it was released to the public in 2014, it replaced other forms of memory both volatile and non-volatile.
Data storage was an important part of computers from the start. Primary storage which is what we think of as computer memory today began in the 1940s. The ENIAC, the first electronic computer, used vacuum tube accumulators to contain 20 ten-digit numbers for simple calculations. In 1949, two Chinese-American scientists invented Magnetic Core Memory. Magnetic Core Memory was the predominant computer data storage format from 1955 to 1975. In 1975, Dynamic Random Access Memory (DRAM) and Static Random Access Memory (SRAM) replaced Magnetic Core Memory. These were based on transistors and became the predominant form of primary storage.
Another branch of data storage was secondary storage. This was not directly accessible to the CPU. For most of the age of computers, the predominant form of secondary data storage was the hard disk drive. It used magnetic disks that rotated fast. As the 20th century ended, the hard disk drive was replaced by the solid-state drive. Early versions of the solid-state drive used transistor-based Flash memory for data storage. By 2009, they were effectively replacing hard disk drives.
Off-line data storage involved an outside source. Early off-line storage used punched cards with data stored on. This was replaced with the magnetic tape which was predominant until the rise of optical discs, like CD, DVD, and Blu-Ray. Throughout the late 20th century, optical discs were the predominant data storage format. As the 21st century began, optical discs were slowly being replaced by USB Flash drives and MP3 players.
One problem with solid-state memory was that transistors could only be shrunken down so far. Too small and they would short-circuit. This was where memristors came in, especially for data storage.
Tech Level: 10
Memristors, as a concept, was first proposed by Leon Chua in 1971. However, the first memristor was created at Hewlett Packard in 2008. It was not until 2014 that these memristors made out of titanium dioxide entered the mainstream. Memristors replaced flash memory in USB Flash drives and solid-state drives. Overtime, they would also replace DRAM and SRAM and all forms of off-line storage. Later memristors would use spintronics to help with data storage. Memristors were used to create neural nets that would bring about artificial sentience. Another application of memristors was the brain-computer interface. Eventually, this would help create quantum computers.