Stanford engineer aims to connect the world with ant-sized radios
news.stanford.edu
news.stanford.edu
1 - It works at about 60GHz. You are not getting a lot of distance or even going through a wall at that frequency and (likely) very low power levels
2 - The devices still need a central "base station". Presumably they rebroadcast to neighbouring nodes; but at lower power levels since they reuse some of the received power for themselves. I doubt you'd get more than 2 - 3 hops out before you don't have much power to begin with.
3 - He cites including these in fridges, coffee makers, light bulbs, etc. None of these are power constrained applications. You can put in $0.45 802.15.4 chip in them TODAY and it comes with a whole microcontroller inside to do what you want to do.
The tech here is no doubt "cool" but I don't see any applicability for IoT. If anything I think it would have some medical uses in pills you can swallow etc. But IoT use is kind of a dud.
Most IoTs have pretty good power source and you can run the w/ existing chipsets.
Unless you have a directional antenna, which these don't, you can not possibly scavenge power and simultaneously hope to increase the range by rebroadcasting.
So rebroadcasting is pointless, these simply communicate with the base station.
But what do they do? I mean it's nice to communicate, but you have to have something to say.
There are others doing work on this for sensors you could embed into say a wall to give you the pressure reading of the concrete (a simple piezo say) but those usually modulate an RF wave (similar to NFC) instead of rebroadcasting.
Sounds like 24 GHz. But all your critiques are still very valid.
But if you can blanket the world with these kinds of radios and mesh them, think 10s or 100s of trillions of radios, then the range issues are less of a concern but you have a chicken and egg problem which needs many many billions of dollars of investment to kickstart. Great reason for IPv6, though :)
In the story those nodes were compute, storage, and transport. As well as interface.
Amazing tech.
I would be interested in trading for a sample, or better yet, the specs of the industrial base necessary to manufacture them.
The whole concept is a bit creepy, but that particular sentence stood out. It's not hard to envision these tiny devices all having microphones and cameras... the Internet of Things That Watch You seems not far off.
Hm. This makes me wonder if you could recover audio from wifi signals.
Bell did a similar demonstration in the 1890s using a mirror to embed reflections in ambient light and demonstrated wireless audio transmission over 200 meters.
However, I'm not sure why audio would cause a frequency shift in a radio circuit. Perhaps you are meaning the antenna will be perturbed and that could possibly be recovered? I'd be interested to know.
The oscillator circuitry of a transmitter is (even when crystal controlled) sensitive to mechanical perturbation, which typically leads to spurious AM and FM modulation of the outgoing signal. To demonstrate the effect I once held a half our session on air with a guy on the other side of the city by just talking to the circuit board.
In a PLL or crystal controlled transmitter modulating the carrier in such a coarse way is much harder. Typically the modulation is done using a capacitive diode (a varicap) which is a diode whose capacitance changes with the reverse voltage. Because this voltage has to be applied to the diode somehow (in the days before SMD) this meant that that wire was again susceptible to microphony because air pressure on the wire changed it's location relative to the ground plane and that caused a measurable frequency shift. Not nearly as big a shift as in the older stuff but it was definitely a factor.
Wifi radios as much more robust than the stuff that I built. But I suspect that given a sensitive enough detector a residual audio component might be extracted from an otherwise non-audio signal by direct interaction between the sound waves and the transmitter hardware.
In a nutshell, it is very much harder to make something that does not exhibit microphony than to make something that does. You'd have to take that into account from the beginning of the design.
I spent a lot of time messing around with toy evolutionary algorithms. I never really got any satisfaction out of those experiments. eventually I found this [1], and felt sort of foolish.
Has anything really happened with emergent properties in the last 10 years or so?
As for feeling foolish after playing with evolutionary algorithms - I'm not the OP but I can relate somewhat given how I saw people learning evolutionary algorithms and neural networks at my university (and I'm pretty sure it's not a local phenomenon). Evolutionary algorithms are usually explained as inspired by biological evolution, with implicit (and sometimes explicit) note that "evolution made us, therefore evolution is superpowerful, therefore evolutionary algorithms - which are just evolution in code - will be superpowerful too!". Except they're not, and the whole concept is bullshit. It's a belief in Random Number God. Throw enough shit at the wall and something will stick. Evolution is terribly, terribly inefficient, and so are the evolutionary algorithms.
Sure, this inefficiency gives them some interesting properties that may help them avoid particular types of local optimas, etc. But those are mathematical features of an algorithm type, and have nothing to do and share no power with evolution, or magic.
The whole problem stems from people trying to transfer virtues of biology to computing by using a surface metaphor. There's a post on LW that covers it nicely:
http://lesswrong.com/lw/vx/failure_by_analogy/
"So... why didn't the flapping-wing designs work? Birds flap wings and they fly. The flying machine flaps its wings. Why, oh why, doesn't it fly?"
Or about neural networks,
"A backprop network with sigmoid units... actually doesn't much resemble biology at all. Around as much as a voodoo doll resembles its victim. The surface shape may look vaguely similar in extremely superficial aspects at a first glance. But the interiors and behaviors, and basically the whole thing apart from the surface, are nothing at all alike. All that biological neurons have in common with gradient-optimization ANNs is... the spiderwebby look."
I encounter a lot of similar "medieval thinking" in CS departments. I don't know why. It probably goes in common with the concept of not caring about how the world works.
Oh, this one is also good: http://lesswrong.com/lw/rj/surface_analogies_and_deep_causes....
[0] - it's also a good trick I picked up while hanging on LW; if you don't know why something happens, label it as unknown explicitly. Say "this process is driven by magic", or "caused by Divine Intervention" instead of trying to invent equivalently-informative but sciency-sounding labels like "emergent behaviour" or "spontanous self-organization". This way you'll never forget that your theory still has holes that need to be filled in, and you won't accidentally confuse yourself (or others).
My point was twofold: a/ beware inference from surface analogies, always strive to understand where the border between similar and different properties lie, and b/ it does happen. People do draw conclusions and build their understanding on superficial analogies in a systematic way. That's why I mentioned the anecdote of CS students I know. I've seen it in real life. Also known as cargo-culting, it's unfortunately not a rare phenomenon.
Also, I'm not the CDDDDARP ((cddddar this-comment)-poster), but I hazard a guess that he "felt sort of foolish" because he discovered he accidentally did some inferring from surface analogies and ended up disappointed.
That said, I don't see why would it need to be passive if it's in a light bulb, or any other device that can be actuated. It'll need more energy to do whatever you tell it to, so it can also use that energy to actively power the CPU.
What's new here?
What's new? Its tiny, and I'm very curious how they got that an oscillator to work at extremely low powers. But, it is really just an extension of RFID/NFC/IoT miniaturization work. But then again, just about everything starts out that way.