The Memristors Are Coming, But Why Should You Care?

The Memristors Are Coming:

The nanotech world is abuzz over a recent announcement that HP will partner with semi manufacturer Hynix to bring memristor memory devices to market within 3 years.

Such a development would be unprecedented. So far, no single component has been able to replace both DRAM and flash. DRAM is cheap but volatile, meaning it loses data when the power is turned off. Nonvolatile flash memory, by contrast, doesn’t need power to retain its data but is too expensive for the volume necessary for main hard disks. (Right now, 250 gigabytes of DRAM costs US $60, but the same amount of flash memory will set you back almost $800.)

In both kinds of memory, data is stored as charge. The problem is that the envelope for the electrons that constitute a discrete charge can’t be made much smaller. That makes it difficult to squeeze more memory into the same size footprint for the same cost. (IEEE Spectrum)

What the Heck is a Memristor?:

Memristors, or “memory resistors,” take advantage of the fact that passing electrical current through particular types of material will change the molecular structure of that material so that it “remembers” which way the current was running, and at what voltage, even when the power is turned off.

Memristors are said to represent a “fourth class” of basic electrical circuit, alongside resistors, capacitors and inductors. The concept behind memristors was first proposed in 1971 by circuit theorist Leon Chua, but for decades it was nothing more than a concept. (Cosmic Log @ MSNBC)

Memristors, like capacitors, inductors, and resistors are passive devices. Passive devices don’t introduce additional energy into a circuit and they don’t have gain — the only energy they need to operate is the signal itself (unlike active devices, which need additional current for biasing, amplification, etc.) They “record” data by having a resistance that changes depending the direction and intensity of current flowing through them. When the current stops flowing, the resistance (high or low in binary, for example) remains in the last state it was in indefinitely, until current is again applied.

Why You Should Care:

Memristors represent a new, all-purpose form of memory that has the non-volatility of flash combined with (eventually) the low cost and speed of DRAM. The other thing memristors have going for them is that they do not store data as charge, and they require a minimum amount of charge to read from and write to, compared to current techs. This translates to lower power requirements (you no longer have to dedicate some portion of your supply to keeping DRAM alive during operation) and denser memories (you no longer have a minimum footprint dictated by the actual size of the electrons comprising the stored charge).

At the moment, it appears HP will be marketing discrete memory modules with this technology, but it is only a matter of time before memristive memory (or Resistive RAM, as HP calls it) is deployed within larger types of circuits, including microcontrollers. Lower power, smaller MCUs with bigger, faster program memories mean smarter, wireless embedded devices. There are still many hurdles to get over before we attain a true Internet of Things, but memristors represent another small step towards a culture of spimes.

Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.

Join 7,500+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython in 2018 – Python on Microcontrollers is here!

Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/

Maker Business — Rethink Robotics closes shop. Long live collaborative robots #makerbusiness

Wearables — Zip it up

Electronics — Serial overkill

Biohacking — Biohacking Resources – Books, Talks and Podcasts

Python for Microcontrollers — CircuitPython creates new assistive tech opportunities

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !


  1. I just had a geek-gasm!

  2. “Right now, 250 gigabytes of DRAM costs US $60”
    Where can I get 1/4 of a terabyte of RAM?? :p

  3. *Face Palm* Why didn’t I think of that…

  4. I think you may be 2 orders of magnitude off. 4GiB of DRAM currently costs about 100USD. So you’re actually looking at 6250USD to get 250GiB of DRAM.

  5. She (Sally Adee, the IEEE author) is talking about DRAM in general, not DDRx SDRAM that you use in a computer. The SDRAM is more expensive because all the chips on a board (and in a pair) have to be matched and satisfy certain timing requirements, plus they have added sychronization circuitry (hence the ‘S’).

    Further, I believe she is referring to manufacturing cost, not retail cost.

  6. When will memristors be available at adafruit?
    I’ll want to use them as soon as they are available.


Sorry, the comment form is closed at this time.