An $80 Open Source Chemical Analyzer

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An $80 Open Source Chemical Analyzer

Posted by Soulskill on Tuesday September 13, 2011 @07:35PM from the great-for-perfecting-that-chili-recipe dept.

An anonymous reader writes "A group of electrical engineering students at UCSB teamed up with some chemists and built an $80 gadget that can check water for arsenic, measure the level of vitamin C in orange juice, and also do simple DNA biosensor tests. The electronics in a blood sugar meter could do all of those things, but their firmware isn't easily hackable. All of the circuit schematics, gerber files, and software for this project are available on their project website. Another team at Denver Metro College is working to improve upon their design. Eventually, it could be used as a teaching tool in chemistry classrooms, or possibly to do blood and water tests in developing countries."

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Of all the research to choose from... by niftydude · 2011-09-13 19:47 · Score: 4, Insightful

UCSB EE department does a lot of great research. Personally, I'm a big fan of the work that they do in GaN and AlGaN devices. But I feel that this story might be the least interesting piece of research being done at the entire university.

Is this news for nerds just because it is open source? I mean - a potentiostat? Really?

Come on slashdot - lift your game.

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1. Re:Of all the research to choose from... by drolli · 2011-09-13 20:55 · Score: 2
  
  i also find it weird. Potentiostats are standard lab-course projects.
2. Re:Of all the research to choose from... by Ihmhi · 2011-09-13 22:57 · Score: 4, Informative
  
  Is this news for nerds just because it is open source? I mean - a potentiostat? Really?
  What measure is a nerd?
  Years ago, I didn't know what "^H^H^H^H^H" meant. (It is, apparently, how one typed a backspace on a rather old type of computer). When I asked what it meant (as it had interested me) I was told by a few kind persons, but I was also chided about not knowing about an obscure computer that was popular before I was born.
  Your nerdiness is not my nerdiness. I personally judge whether or not a story is good for Slashdot by the likelihood of seeing it on CNN (when it isn't related to a major event such as a natural disaster or a major product release). Would you see anything like this on the front page of Faux News or even a much more reputable outlet like the BBC? (According to my BBC RSS feed, the answer is firmly in the negative.)
  Geek culture is a mysterious, ethereal thing that spans interests of many different types and complexities. Ignore a story about something that doesn't interest you, sure - I don't read 3/4 of the articles Slashdot posts - but please don't chastise them for actually posting something that's relevant to using technology (cheaply!) to do something cool that will actually help people. Strike that last - just using technology to do something cool.
  Hey, at least it's not a story about Bitcoin or the latest Apple drivel.
  
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3. Re:Of all the research to choose from... by ZeroExistenZ · 2011-09-13 23:21 · Score: 2
  
  Years ago, I didn't know what "^H^H^H^H^H" meant. (It is, apparently, how one typed a backspace on a rather old type of computer).
  It's nostalgia around old terminal machines. It's an old type of nerd who would appreciate that humor as it clicks with their generation of computer discovery and use. It also establishes a connection amongs the nerds who had the same type of PC usage style and belong to the same "PC Universe".
  
  Your nerdiness is not my nerdiness. I personally judge whether or not a story is good for Slashdot by the likelihood of seeing it on CNN
  You are a "young nerd" if I read that. There was a day everything newsworthy and nerdy (deep specialized) would be found first here (now it is watered down and less exclusive I believe). The internet was a bit the back-room hangout were nerds were doing their things and communicating about it. Often in connection with research themselves posting the cool thing they were doing or have done. CNN and other "general information sources" were often mocked and considered inaccurate.
  
  Geek culture is a mysterious, ethereal thing that spans interests of many different types and complexities.
  I believe a geek used to be someone with a deep fascination about a subject and spending alot of time going deep into it. Say, the "Nintendo" or "Star wars" cultures.. They unite those who were taken by it. The aspect of being highly appreciative about those things and have this overly nostalgia or focus on it is more likely by "geeks" giving them culture. (I myself am 29, Nintendo is deeply ingrained nostalgia for me)
  
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4. Re:Of all the research to choose from... by zippthorne · 2011-09-13 23:43 · Score: 3, Interesting
  
  It's not an "obscure computer" It's the very computer you're still typing on
  ^h = control key + h. The "trick" you probably don't know is that control + character combos are shorthand for ascii control characters. Specifically, the characters a-z correspond to 1-26, and a few off the surrounding keys also map to control characters (there are 32 total control characters)
  You will find that, in windows programs like Word, etc, many or all of the combos are trapped, and made to do other things that may be more useful to the user, but in, say, a command window, the ones that make sense there will do what they always did.
  It's not relevant to many of your current tasks, but it's not so far obscure that you couldn't even experience it any more. In fact, I use about ten of them every day working with .. an obscure, proprietary program needed for work that apparently was implemented as a terminal program. For instance, It turns out that u,d,l,and r map to the same ascii control characters as the up, down, left, and right arrow keys, and it happens that I hate moving my hands off of the home row if possible.
  And.. you know what.. forget everything. It looks like you meant to say, "obscure computer trick," which is pretty true at this point.
  
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5. Re:Of all the research to choose from... by bgat · 2011-09-14 01:44 · Score: 2
  
  It isn't a completely open source project, as they used a closed-source program to capture the schematic and board layout. EagleCAD is a proprietary program that runs on certain versions of Linux, but the file format is proprietary. The no-cost version of EagleCAD limits the size of the circuit, I haven't checked to see if CheapStat's circuit exceeds that size, or not. Regardless, if you want to modify the circuit then you are either downloading/buying EagleCAD and continuing to lock up your design, or you have to re-capture the schematic in a truly open tool.
  gEDA would have been a better tool choice for schematic capture and layout, in my opinion. And the result would have been truly open, as the file formats it uses are documented and text-based. Aside, I have used both EagleCAD and gEDA, and much prefer the latter due to its flexibility and open file format.
  It's nice that they provide complete schematics in PNG, however. No complaints there.
  
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6. Re:Of all the research to choose from... by bgat · 2011-09-14 01:46 · Score: 3, Insightful
  
  Is this news for nerds just because it is open source? I mean - a potentiostat? Really?
  This one is driven by a microcontroller, which is a nice touch. So, yeah, I think it rates high enough on the nerdiness scale to merit publicity.
  
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  b.g.
Credit for open sourcing by ramk13 · 2011-09-13 19:48 · Score: 3, Interesting

What this group should get credit for is open sourcing a cheap design.
The chemistry and circuit design involved are well-established and taught at the undergraduate level. You can easily find schematics for potentiostats online. It's reaching to say that they've built an $80 chemical analyzer, because a lot of prep work and specialized electrodes (platinum!) are needed to run some of these analyses. This is a cheap lab instrument, not something you take out in the field to make measurements. Ruggedizing and standardizing reagent solutions are what would make a field instrument much more expensive.
I'd bet the group didn't make an exaggerated claim, it's the unfortunate nature of science reporting.
1. Re:Credit for open sourcing by bill_mcgonigle · 2011-09-14 05:15 · Score: 2
  
  because a lot of prep work and specialized electrodes (platinum!) are needed to run some of these analyses
  Ah, thanks for the clarification. I'm always on the lookout for a cheap melamine detector, but it looks like I still need to save up for a mass spectrometer.
  
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Everyone is missing the point of the article. . . by MagusSlurpy · 2011-09-13 21:29 · Score: 5, Insightful

The reason it was published is because it provides an excellent tool for teaching undergraduates about the intricacies of scientific instrument design. It's not ground-breaking, it's not revolutionary, it's simply an experiment to teach sophomores and juniors about voltammetry in a cost-effective way that will hopefully stick with them more than "Here, watch quietly while I use this $75K cyclic voltammeter that we aren't going to let you use because undergrads always screw it up and we can't afford the week it takes to get it calibrated and functioning properly again."

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Re:Everyone is missing the point of the article. . by Savantissimo · 2011-09-14 00:05 · Score: 2

It was done a bit better than most such projects- it had a case, display, mini-control joystick, mini-USB jack, basic software and firmware, they tested it in several experiments beyond the basics - the DNA analysis was particularly slick. More effort should have been given to coming up with a useful set of electrodes and reagents and a proper connection from the instrument to the electrodes - alligator clips are a bit below the standard of the rest of the project.
I'm just an armchair engineer, but I suspect the electronic design could be improved a good deal with modest extra cost. A proper electrometer-grade op-amp, using proper guards/shields on the circuit board for the op-amp inputs, preferably not running the working electrode input through a switch (though I'd have to think harder to see if it's really a problem as they are using it, charge injection could be a worry), better insulation and electrode connections on the cables, using a uC with built-in USB, (perhaps an ARM from STMicro similar price, it also has better ADC and DAC, 32bit, faster clock, more RAM and more flash), and maybe a precision voltage reference and a couple of trim pots. This really isn't suitable as a portable instrument as they were using it, though I suppose some people might do so . As a bench instrument with a computer connection the expensive screen could be dispensed with, and DC-DC converter might be replaced with a simple regulator. The case is big enough to stuff full of batteries, and they give a much longer lasting and less noisy power supply than a single-battery & converter setup for a portable device, and for a bench instrument USB power should be sufficient. The ferrite on the analog ground with the double HF/LF bypass caps is a very good thing, but feeding it through a separate, battery analog supply would be even better.

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$50 open source neural net sensor by MountainLogic · 2011-09-14 03:31 · Score: 2

You can get a spayed or neutered open source self-propelled, neural net controlled chemical sensors from the the humane society for about $50. With a little training of the neural network using some bacon and a chew toy it can detect just about anything airborne. Plus you'll have a hard time building anything with a better low end sensitivity. Put out a little food on the back parch and you can likely snag an open source neural net sensor for free. Before acquiring such a sensor unit be sure to check you landlord's sensor policy. Seriously, how we ever made a living while hunting on the savannah with our snoozes is beyond me.