I just came back from HP TechCon 2008, Hewlett-Packard’s internal conference for technologists, which was held in Boston this year.

HP TechCon is something serious. It works like a real conference: you have to submit papers to be invited, there is a formal selection process, and technologists end up presenting their work to a wide audience.

The two differences with other conferences are what makes it very interesting:

- it’s internal to HP, so we get to see and talk about stuff that is confidential or really far out.
- It’s all about HP, which is a big company, so there are a lot of different topics. Most conferences are really monolithic by comparison.

#### Meeting great people

Obviously, there is a lot I can’t talk about. But I can at least say that it was the occasion for me to meet many amazing people. Below are some public links telling you more about some people I met there:

Phil McKinney is the VP and CTO of HP’s Personal Systems Group. He has a blog, a Facebook profile, a Wikipedia entry, publishes podcasts, has more than 500 LinkedIn connections, and even a Google Phil entry on his web pages. Recommended reading.

Exploring the web around Phil’s blog and comments, I discovered a number of things, like mscape and the HP Game On series of ads. And for serious gamers, the Blackbird 002 game system (adding “002” to the name is, by itself, a really cool piece of serious geekery.)

Duncan Stewart is a physics researcher at HP Labs. You need to add “memristor” to Google Duncan, because there are other people with the same name. Occasional readers of my blog may know that physics is a topic I’m quite interested in. He’s one of the researchers behind the memristor, which I will talk about below.

There are a number of pages about Duncan Stewart, including this one on the HP Labs web site. I really enjoyed talking to him.

#### The memristor

In case you did not hear about it, the memristor is the fourth passive device, after the resistor, the capacitor and the inductor. But it would be surprising if you had not heard about it. The number of papers and articles on such a recent topic is really amazing. Here is a link at HP Labs, the article in Nature that I think started it all, or the Wikipedia entry.

To explain what the memristor is, a little hydraulic analogy is in order. As you know, a good way to think about electricity is to see “voltage” as the height of water (the pressure, really), and “current’ as the flow of water.

- A resistor is like a grid or something that blocks the flow: to get more water to flow through (more current), you will need a higher level of water (more voltage). This is expressed as Ohm’s law , .
- A capacitor is like a tank, where inbound current elevates the level of water, and outbound current depletes the contents of the tank and therefore the level of water. Therefore, it relates a
*change*in voltage to a current, , which you can also write as - An inductor is like a heavy paddle wheel in a current, which prevents it from changing quickly. In that case, changes in current are related to the height of water: if you try to reverse the current for example, water will accumulate until the paddle wheel changes direction. This is traditionally expressed as , but you can also write it as
- Finally, a memristor is like a gravel-filled pipe near a constriction. If flow brings the gravel towards the constriction, the gravel blocks the pipe and the resistance to flow will increase. On the other hand, if the flow brings the gravel away from the constriction, water can flow freely. This relates a change in current to a change in voltage, which you can write as .

The equations show why this is the “fourth passive element”: if you consider current and voltage, and accumulated current and voltage, there are four ways to combine them.

#### Fine, so… what do you do with it?

So… why does it matter, what’s the big deal? Well, very simply put, the memristor looks, among other things, like a very cheap and dense way to build memory devices. There are still a good number of questions to be addressed before this unseats Flash memory and other persistent storage, and to be honest, there is even a small chance that it never will (the hard disk is still with us, no matter how many times its death was predicted.)

There are many other applications as well. One of them, “artificial intelligence”, looks a bit overhyped to me at the moment. What seems true, however, is that memristors might enable cheap neural-like circuits to be mass-produced efficiently.

#### Conclusion

This was overall a great TechCon. Still, I’m glad to be back, it was exhausting.

hi – awesome post, and thanks for the link to my Memristor article.Sounds like TechCon was a blast.Jamie

Chaise Lounge Says: Wonderful post!