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All Over But the Funding: Open Hardware Spectrometer Kit
New submitter mybluevan writes "The Public Laboratory for Open Technology and Science is putting together an open hardware spectrometer kit
on Kickstarter. The kits are built using an HD webcam, discarded DVD, and a couple other odd bits. They've also put together a kit for your smart phone and open-source software for desktop, Android, and iOS. Need to analyze the contents of your coffee, the output of your new grow lights, or a distant star on a budget? Just build your own spectrometer, or pick up the limited edition steampunk version."
Besides making cool hardware, they'd like to "build a Wikipedia-style library of open source spectra, and to refine and improve sample collection and analysis techniques. We imagine a kind of 'SHAZAM for materials' which can help to investigate chemical spills, diagnose crop diseases, identify contaminants in household products, and even analyze olive oil, coffee, and homebrew beer."
A use for all those Windows ME disks!
(You need a DVD as a diffraction grating.)
Faster! Faster! Faster would be better!
Ok, they've got a few days left, but they've currently got $72000 vs. their $10000 goal. Cool project, interesting applications.
(But since we're talking Kickstarter here, I'd like to put in a plug for the Drip Clip kickstarter. They've designed a small drip-counter to be used for measuring medicine in intravenous bags, especially for applications like disasters, third-world hospitals, and the like. The prototype used Arduinos and baling wire, but the production version is going to be manufactured plastic with a simple count-down display on it.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
But ... that's an interesting idea. I think that's worth a six-pack worth of funding.
Did I get a first post? Are the trolls and the GNAA spammers asleep? Or, preferably, dieing slowly?
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
Back when I was in University in 2001 (U Waterloo - Independent Studies) one of the guys found a spectrometer for sale at the weekly physical plant surplus sale for fifty bucks so he just set it up in the IS lounge (which was in the middle of the Psych building) so people could come in and analyze whatever they wanted. It was great for inviting hippies in to charge up crystals with very specific wavelengths to increase harmonic resonance.
I pitched in (and hope to get one of these), after having done one of the online instructions for a very rough looking one. It seems like the sort of thing that will net me hours of goofing off for very little money. ;)
That Drip Clip sounds pretty cool, though it looks like it's IndieGoGo, not Kickstarter: http://www.indiegogo.com/shiftlabs
Unfortunately, $75 is a bit out of my funding range. Otherwise it'd be a nice little sensor to play with.
I did my PhD on a topic that involved building some gear related to spectroscopy. A good deal of my work involved cludging together optical parts from seemingly unrelated sources. As such I just love this sort of thing. Unfortunately I have to agree with the above commenter that the precision is just not going to be good enough from a webcam for real chemometric measurement. However with a little more investment the precision could be improved. The real difficulty will come from the need to calibrate the thing. You need to know exactly where each wavelength of interest is centred ** exactly** on the sensor at the time of measurement and this is not a trivial task. Unfortunately proper calibration is so often just not achieved... and that's not even beginning to consider the issues of background/ stay light, Johnson noise etc. I suppose this design could be used for crude detection like the article says rofl.
Lots of people have been working in this field. The most impressive results are achieved by the astronomy community. link It is possible to produce a home made spectrometer that gets useful results. Some of these are capable of resolution sufficient to identify chemicals. These are sophisticated and often use a peltier cell to cool the CCD in order to reduce noise. link
I did a project whose aim was to produce a cheap spectrometer to match paint colors. link The problems I found were:
My own engineering trade-off was sensitivity vs. resolution. To get spectra for dark colored paints, I widened the slit which reduced resolution. That, as far as I could tell, was reasonable because I wasn't trying to identify chemicals and the spectra from paints weren't particularly sharp.
The folks in TFA have a site where people can upload spectra. That's fine but a huge database of spectra is not too useful. The spectra have to be organized somehow. Here's an example. In fact the problem can be quite daunting
Really the very first picture they showed of the spectra and the resulting plot on the very top of their kickstarter page has the graph backwards compared to the visible spectra.
With such an epic facepalm I'm surprised they know what a spectrometer is.
Not nearly enough.
Near IR (900-1300 nm) is the best you can hope for with a camera chip as a detector. Yes, you can sort of/kind of do a bit of "fingerprinting" there, but 10 nm spectral resolution won't cut it for this kind of application. On a side note, I seriously doubt they can get 10 nm from a CD as a diffraction grating.
To go for the traditional IR fingerprint region, they will need to look at the region between ~6000 and 20000 nm, which is decidedly not something you can do with a webcam chip. You need a *very* special kind of sensor for that. For the reference, a reasonably specced IR spectrometer will cost a tad over $10K. Most of this money will go towards the hardware, that is the sensor and the optical bench.
I wish it was really possible to identify "toxins" with a simple visible light spectrometer. I have one of these el cheap machines in my lab:
http://www.chemglass.com/product_view.asp?pnr=CLS-4047
They are only useful for measuring concentrations of very, very specific compounds under very specific conditions. We also have an $15K IR machine, as well as two mass spectrometers and routine access to 7-8 $1M NMR spectrometers. Sometimes this is enough to analyze practical samples, and sometimes it isn't.
When it is not working out for us, it is not a software problem.
It is clear to me that the people behind this project are, unfortunately, out of their depth.
I don't want to sound all negative here, but... I don't have a choice, do I? A visible light spectrophotometer will not "detect toxins", no matter how much you try to make it open-source or crowd-sourced. The very concept of identifying compounds by visible light absorbance is very much flawed. Thing is, *most* molecules will not absorb visible or near UV light in a way that is specific enough. Real Chemists (TM) traditionally use the so-called IR fingerprint region for this purpose. This region is from approx. 700 to 1500 cm-1 (about 6 to 20 uM - that is 6000 to 20000 nanometers). A special detector is needed for these wavelengths. The one we have in our lab is cooled with LN2 and costs south of $15K. We also have a UV-Vis spectrophotometer, which has its own purpose. That purpose is not "identifying toxins", or analyzing any unknowns. Now, on to my next point. Identifying molecules is challenging, because they are very, very, very mindbogglingly small. Chemists have been grappling with this challenge for a long time. There are many spectrometric methods out there, including IR and UV-Vis (briefly discussed above), near-IR (900 to ~1800 nm, useful for *some* fingerprinting), and NMR (60-1000 MHz, very informative, bit needs a BIG magnet). Spectral data for many molecules of interest has been compiled into readily accessible databases, and is easily accessible. Some of the databases are proprietary/pay-per-view: https://ftirsearch.com/features/libraries/sea407.htm Some are semi-public: http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/direct_frame_top.cgi And some are government/public: http://webbook.nist.gov/chemistry/ The people who started this project do not seem to grasp of the very basic concepts of chemistry, nor did they do any research on the subject. Reading a Wikipedia article on UV-Vis would have been a good start. What is even more disconcerting is that the fundraising effort behind this cardboard spectroscope has been a success. One just has to hope that nobody buys this to screen their food for "toxins", or to teach their kids chemistry.
Disclaimer: I'm no expert in spectroscopy.
Would it be possible to estimate the blood's sugar content with this kit?
It is possible non-invasively with Raman spectroscopy in the infrared:
http://www.popsci.com/technology/article/2010-08/mit-glucose-meter-checks-blood-sugar-levels-painless-ir-light
The usual blood glucose meters have errors of up to 50% in the reading. And they still require those expensive analysis strips.
If a home blood glucose measurement would be possible with one of those kits (even if you still need to draw blood), that would rock.
The brass-and-wood "steampunk" version is limited edition, but only limited in that we're only selling 5 pre-built spectrometers. The designs are already online for most of these models and based on the early build photos and bill of materials you can build your own (under the CERN Open Hardware License). So it is open hardware -- have fun!
They've got an interesting stretch goal though: "if we get to $100,000 -- a 'stretch goal'. In the spirit of enabling open collaboration we'd like to make it possible for people to make their own Spectral Workbench-based apps". I'm thinking a Spectral App Platform API would be pretty sweet. "Imagine a "Spectral App Store" where wine enthusiasts can develop their own testing suite for wines, gardeners for grow lamps, and coffee connoisseurs for coffee -- each looking for specific wavelengths or patterns *specific to that application*." They're not that far away from it either.
As late as the 1990s I used a portable optical spectroscope with a battery to strike an arc and a book full of photos showing where the lines should be for specific elements for alloy identification. I only used it a couple of times and didn't get the hang of it, but apparently some people got useful results from it to the point of estimating percentages of elements instead of just seeing if they were present.