Caltech Creates Electronic Nose

eldavojohn writes "Researchers have created an electronic nose that can detect odor and identify which odors are a concern to it. From the article, 'The Lewis Group a division of Chemistry and Chemical Engineering at Caltech have a working model of an electronic nose. The efforts of Caltech scientists has led to an array of simple, readily fabricated chemically sensitive conducted polymer film. An array of broadly-cross reactive sensors respond to a variety of odors. However, the pattern of differential responses across the array produces a unique pattern for each odorant. The electronic nose can identify, classify and quantify when necessary the vapor or odor that poses a concern or threat.'"

Comments

Why fix what isn't broken?

[TheTopher]

As a student at Caltech in Prof. Nate Lewis' Chemistry class, I feel obligated to ask why the correct spelling of "Caltech" from the article was converted into the incorrect spellings of "CalTech" and "Cal Tech"? I realize that we don't conform to the usual abbreviation for Tech schools but it's a "little t" for "Caltech"

Re:Why fix what isn't broken?

[teslar]

But is the chemical the smell, and is the wavelength the colour?

Well, yes, since these represent the necessary and sufficient stimuli for you to perceive the smell as the smell of roses or the colour as the colour red. I don't think there's a need to go philosophical on this point.

What you are really talking about, I think, is the experience of perceiving a smell or odour. Then it's very clear that everything depends on who is doing the smelling/looking and nobody is going to argue that electronicc noses experience these stimuli in the same way we do. So yes, an electronic nose would have a priori problems with qualifying smells in subjective ways (smells good, bad, refreshing, stale) unless you specifically train it with lots of examples from all those categories. But that's not really the point of an electronic nose, it's more about detecting toxins and perhaps reverse-engineering certain odours (e.g. just what did the chef put into that lovely sauce of his?).

I also wonder how it works on things where the 'known' composition can vary. Will it mis-identify them like some other robot did identifying a reporter's hand as bacon (or something similar)?

It depends on what you want to do. If you want to identify a complex odour based on the mix of chemicals you've encountered, then yes, that can happen.
When you design such a system, you take lots of samples from all the inputs that vary so that you get a good idea of the possible variation for every given input (so you train the system with 50 roses, tulips and pieces of bacon instead of just one each). If you were to plot the inputs in a multidimensional space (one dimension per chemical you can detect, and the metric is the concentration of said chemical) you would thus not get e.g. a single point for the odour 'rose', another single point for the odour 'tulip' and a third point for the odour 'bacon'; you would get entire clouds of points.
If you're lucky, there will be plenty of empty space between the clouds and then you can easily train a classifier to discriminate between the odours (sometimes as simply as computing the distance between the odour you detect to the centre of each cloud and going for the closest cloud). If there is some overlap, you can still train a classifier and will be alright most of the time, just sometimes you'll have to qualify your ouput with a probability if your input falls into the overlap region (80% chance it's a rose, 20% it's a tulip). If there is heavy overlap, you're pretty much screwed unless you can think of a funky nonlinear transformation of the input which achieves a better separtion of the the different classes.

So yeah, misclassifications can happen, it depends on your input space and how the classifier deals with it. Especially novel stimuli can be a problem, I'd imagine.

Re:Why fix what isn't broken?

[3.1415926535]

veryone who went to Caltech was a student of Nate Lewis. He teaches the required freshman introductory chem class.

Artificial Nose

[sqrt(2)]

I've always thought it interesting that creating an artificial nose (sense of smell) has lagged so far behind the other senses. Vision, that's easy, cameras have sharper resolution than our pathetic biological eyes. Hearing, again, sensitivity of microphones has easily surpassed human ability. There's the sense of touch, but we can cheat and make sensors that detect resistance to motion, being able to feel and discern texture is harder however. Sense of smell is probably the most abstracted and subjective, so it's no wonder it's the most difficult to replicate with technology. Most of the artificial "nose" tech is just checking for the presence of certain chemicals in the air.

Re:Artificial Nose

[allcar]

Similarly, use of odour in entertainment is way behind the more "mainstream" senses. There are a few museums that have used smell as part of there displays - The Imperial War Museum in London is a good example. The 1st World War trench exhibition uses artificial smells to bring you that delightful blend of excrement and cordite.
However, in general films and games have steered clear of the sense of smell. In gaming, visuals and sound are a given. Vibrating controllers try to deal with the sense of touch. Smell (and taste) have been ignored. As usual, it will probably be porn that leads the way - just think of the possibilities!

Re:Artificial Nose

[Mathinker]

It's also probably the sense which has the greatest genetically based phenotypical variation. To put it simply, there's probably more average difference between "normal" individuals' olfactory experiences than those of sight, hearing, taste, and touch.

That might just be because we rely so little on smell, what is accepted as normal has expanded with respect to this sense (as opposed to color-blindness, for example).

Re:Artificial Nose

[cashdot]

It is off-topic, but I could not resist: I don't think that cameras and microphones have surpassed the human capabilities. Show me a microphone that has the same dynamic range as the human ear. Or a vision system that has the same 'postprocessing' capabilities as our visual cortex. Resolution and sensitivity are not the only performance indicators!

Re:Artificial Nose

[phozz bare]

As usual, it will probably be porn that leads the way - just think of the possibilities! Like, ew?

Re:Artificial Nose

[crontabminusell]

Vision, that's easy, cameras have sharper resolution than our pathetic biological eyes. I wondered about this, so I decided to look it up. At http://www.clarkvision.com/imagedetail/eye-resolution.html the writer seems to sum up the topic pretty nicely. It seems that, while our eyes have probably been surpassed by technology when looking at resolution only (think http://www.gigapxl.org/ ), the image processing power of the brain exceeds any of our current technology. I guess our eyes aren't quite obsolete yet. ;)

Old news?

[ledow]

Am I the only person (in the UK) who saw the Tomorrow's World back in the days of Phillipa Forester or earlier where they had something IDENTICAL to this and were "on the verge" of commercialising it.

I seem to remember something about they discovered the material being tested for aircraft use until they realised that the strong odours of a busy airport made the properties of the material change, then they put it into an electronic nose. I also remember a demo where the machine detected the difference between "normal" and "rancid" mayonnaise by smell alone.

It seems that this is one of those inventions that just keeps popping up but nobody ever really finds a commercial use for it that can make all the development costs worthwhile.

Re:Old news?

[OlRickDawson]

I've read about different electronic noses before, yes. My impression of this article is that this is an improved version, with a wider range of detection, and cheaper to make.

Re:Old news?

[Mr. Underbridge]

Am I the only person (in the UK) who saw the Tomorrow's World back in the days of Phillipa Forester or earlier where they had something IDENTICAL to this and were "on the verge" of commercialising it.

This is in fact old news. The first publication from this research group regarding chemical sensing was in 1995. I don't think any major breakthroughs have been made recently.

See http://www.pnas.org/cgi/content/abstract/92/7/2652

That's not to say it isn't interesting - I have experience in the chemical sensing field so I think it's cool - but it's definitely not news.

Hold it in

[doyoulikeworms]

Because futuristic elevators are going to be really awkward.

Medical applications

[apodyopsis]

It is well known that dogs keen sense of smell can detect illness and cancers. Lets hope this thing can be turned into something sensitive enough and cheap enough for widespread medical use. This could save lives.

for the interested: http://news.nationalgeographic.com/news/2006/01/0112_060112_dog_cancer.html

Now they can build the Smelloscope

[Gar0s]

FRY: This is a great, as long as you don't make me smell Uranus. Heh heh.
LEELA: I don't get it.
PROFESSOR FARNSWORTH: I'm sorry, Fry, but astronomers renamed Uranus in 2620 to end that stupid joke once and for all.
FRY: Oh. What's it called now?
PROFESSOR FARNSWORTH: Urectum.

One step closer to Lt Cmr Data

[master_p]

If all the electronic vision/sound/touch/smell data could be put in a computer which had a simple program of recalling reactions according to those data, we could have the foundations for an electronic brain.

And if the reactions are driven to motors which could move body parts, then we are one step closer to making an android.

Electronic Noise

[Esion Modnar]

is what I at first thought they had created. I was not impressed. Then I realized it was an electronic *nose*... Still not impressed.

Yup, a decade at least

[Colin Smith]

I actually worked in the lab where they developed the machine. UMIST in Manchester.

They did commercialise it. The technology is used all over the place.

http://chemse.oxfordjournals.org/cgi/content/full/30/suppl_1/i252
http://www.wordspy.com/words/noseonachip.asp

Of course, I'm sure Caltech can patent it can sue the bastards into oblivion.

Something similar

[curious.corn]

Something similar, the Libra nose has been developed in Italy, at the University of Rome "Tor Vergata". The article is slim on the transducer CalTech is using...

Unwired Input

[Doc Ruby]

Where's the cocaine transistor?

Is it secure? Can it be picked?

[benow]

Sorry, couldn't resist.