HP scientists have discovered some key elements of the workings of "memristors," the fabled fourth fundamental circuit element, which could lead to the technology replacing current types of Flash memory, and possibly even inspire computer systems that work more like the human brain.
A memristor is a "memory resistor," a fourth circuit element alongside the more familiar resistor, capacitor, and inductor. What separates a memristor from a resistor is that its resistance changes with the current passing through it. A different current results in a different state, and the memristor remembers that state even after the current is gone. First proposed in 1971, the memristor was finally proven to exist by HP in 2006, and the company has been leading the charge in researching the technology since.
In a paper for the journal Nanotechnology, the HP researchers describe how they were able to use x-rays to examine the structure of a memristor. They found that current flowed into a 100-nanometer-wide channel, and that the current produced heat, which caused the titanium dioxide surrounding the conducting channel to change to a non-conducting state.
"With the information that we gained from the present study, we now know that we can design memristors that can be used for multi-level storage," HP's Stan Williams told the BBC. "That is, instead of just storing one bit in one device, we may be able to store as many as four bits."
Memristors have a lot of potential practical applications. Their properties—in particular the ability to switch on and off in a nanosecond—have advantages over current NAND Flash memory, the most popular kind of memory in portable devices. Since there's nothing exotic about what memristors are made from, today's chip factories could easily make memristor chips; they just need a design.
The nature of memristors allows them to both store information and perform processing, which could lead to new types of electronics where computations are performed in the same location where the information is stored. Eventually, they could replace DRAM and even hard disks.
On top of that, there are more levels to a memristor's state doesn't than simply be "on" or "off," which is similar to how synapses in the human brain work. Although a long way off, memristors may one day be a key element in designing machines that actually think.
For now, though, the nascent technology is still on the road between theory to practice. One of the first applications of the technology will probably HP's server business, where memristor-based systems could lead to implementing high-performance computing (HPC) in the cloud. (source : pcmag.com)