Public Lab Research note

Spectrometer Kickstarter script

by warren | August 01, 2012 15:17 01 Aug 15:17 | #3063 | #3063

I'm getting ready to post a Kickstarter campaign to make a whole bunch of PLOTS spectrometers and get more people involved in that project. I'm trying different reward structures and rejiggering the script a lot and thought I'd share what I have to see if people have input.


(Updated with feedback)

$10 - A fold-up spectrometer attachment for your smartphone. Ships flat -- you cut it out and assemble it.

$35 - A proven and tested "desktop" USB spectrometry kit which you assemble inside of a VHS box. 400-900 nanometer range and 3-10 nm resolution. (please add $10 for international shipping)

$60 - An experimental "backpack" which clips to your Android phone's camera and turns it into a spectrometer. If more than 250 backers want this, we pledge to develop a native iPhone app as well. (please add $10 for international shipping)

$100 - All three of the above - (please add $60 for international shipping)

$300 - A fully-assembled and calibrated "countertop" model with Pyrex sample dishes and a full-spectrum lamp. Would look great in a coffeeshop, a wine bar, an exhibit or classroom. (please add $40 for international shipping)


A spectrometer is a tool used to identify a substance, usually by measuring the colors it absorbs. (oversimplification!)

A prism splits the colors so that each can be measured separately.

Show: bulb + DVD clip

Light passes through a sample, and some colors are absorbed. If you graph the brightness of each color in the spectrum -- like the EQ on a stereo -- the resulting spectrum is like a fingerprint, helping you to identify what was in the sample.

Show: diagram


( we think everyone should have one?)

The Public Lab, our open source community (join us!) started working on spectrometry during the BP oil spill, when it was expensive or impossible to prove that some pile of brown goo was actually oil, and actually from the spill.

Show: adam with backpack spec

Unfortunately, spectrometers cost thousands, sometimes tens of thousands of dollars, so only well-funded scientists get to use them. There are no consumer spectrometers, and today's tools are not only expensive, they're hard to use.

But we are surrounded by mysterious substances, from environmental disasters to household chemicals and foodstuffs. A spectrometer is kind of like a tricorder... an essential tool in investigating unknown substances.

So, we designed and built our own. How does it work?

How? Explain our spectrometer design

Show: spectrometer walkthrough images

Working together, we've developed a simple kit built from a webcam, a VHS box, a DVD, and a piece of black card paper.

Show:2 olive oils

Two olive oils -- visibly indistinguishable -- but their spectra help tell them apart like a fingerprint. The same principle can work for oil contamination and other identifications.

Show:graph of different olive oils

We're using olive oil as a safe test material because our dream is to ID petroleum contamination. But a slightly different technique has already begun to show promise for identifying a variety of oils. Watch how this green laser produces a distinct colored glow in each of these samples of oil -- from tar to motor oil to olive oil. We're working to measure their spectra, and soon hope to have a simple test to distinguish motor oil from crude, or coal tar.

Other uses

Using our DIY spectrometer and our online analysis tool, Public Lab contributors have found a variety of other uses:

  • Wine (already done), and vineyards already use more expensive spectrometers to analyze wines.
  • Coral/aquarium lighting, grow lamps
  • Finding dyes in detergent
    • Public Lab contributor JoshMC used his spectrometer to test the Free and Clear detergent he's using for his newborn's diapers. Turns out it had a bluing agent to make whites look whiter.

How can you get involved?

We're looking for people to help test and refine these open source techniques and tools, so get a kit or build one yourself and start collecting samples.

We hope to build a giant open source database of spectra at -- a kind of YouTube of spectral data which can be used to ID environmental contamination, as well as help people analyze things around their home, like detergents, fishtank lights, even wines and beers.


To this end we have two different spectrometers. The first is the desktop spectrometer kit we've already developed -- for only $30. It has spectral resolution of up to 1 nm -- better than many $70,000 devices. We can assemble and ship these soon after the Kickstarter ends.

The second device is just a prototype -- it's a small extension which clips to the back of your phone, turning it into a mobile, handheld spectrometer. Right now it works on the Opera browser on Android, but if we sell more than 1,000 of these, we pledge to develop a native iPhone app as well.

So join us now to improve these open source devices, and to collect spectra of all kinds of things -- invasive species, coffee, agricultural runoff, oil stains, microbrewed beer, fishtanks, grow lamps!


So Chris F has been offering some good feedback and I am leaning towards doing a very cheap cardboard cutout spectrometer and a more expensive injection-molded or 3d-printed one... the tough part is that we cant do those processes unless we have a lot of backers, so there's a certain threshold we need to meet. 3d printing costs ~$10-20 each depending on how it's done, and that's just at cost. Injection molding takes around $5-10k absolute minimum just to get started, but per-unit cost is much lower, say, $1-3 ? These are just ballpark figures.

As to the iPhone/Android thing, I am very opinionated about the closed iOS system and so i'm conflicted -- although it's easier and more open to develop just for Android (which is why i did it first) I do want to help people who have iOS devices. But it feels "wrong" to set that up as an "extra reward" as if to cast an iOS version as "even better" which I strongly believe it is not. Still, the main reason I am thinking of having a cutoff is that I only want to devote the time if there is a strong demand. This may also drive people to get the word out more.

Anyhow i'm all up in the air on this and haven't made any final decisions. Any input is appreciated and there's still some time while I'm finishing up the video.

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OK here's the preview (very rough cut) of the beginning of the video. I'm boosting the volume in the next draft so if it seems quiet, it'll be dealt with in the next revision.

I'm also looking around for some good music to put this to.

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I like the general flow... but it seems targeted towards a general audience (people getting their first spectrometer, intro to spectrometry) I'd mention that there are other DIY spectrometers out there, that you were inspired by them, and over the past two years, you've done the hard work of calibrating this one.

it's mentioned briefly that people getting these kits will help with the tool development, but I think it's worth going deeper there-- like, "we did the hard first steps of calibration, and now we need your help to build a database of spectra. With your help we can scale up and begin tackling tougher spectra, like the oil contamination that inspired us to start researching spectrometry."

that kind of forward-looking call for assistance can give it a bigger context beyond just "hey this spectrometer is fun around the house" to "have fun around your house and contribute to an EJ-focused civic science initiative."

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I like the idea of better emphasizing the "invite others to join/contribute" angle. When you look at what's novel, there are a few things:

  • shared database, community
  • open hardware
  • good software (getting better)
  • EJ angle

i.e. it's not just a proof of concept, it's part of a different way of thinking about why spectrometry is important, and a different paradigm for sharing/exchanging/communicating about results (more YouTube or Wikipedia, less cloistered/experts-only)

Emphasizing how much is left to get done and asking for help is also a great way not to overpromise what it can currently do -- I'm concerned about saying "this thing can already do x,y,z!!! it's teh bomb!" and losing credibility that way. I want constructive skepticism as much as enthusiasm. So i'll rework the script to reflect that, thanks.

A couple other things incorporating Chris' feedback on pricing/materials, and some of Christina Xu's on user-readiness:

1) I'm going to divide the mobile version into a super-cheap folding black cardboard version at ~$5-10 or so (pricing thoughts?) and a fancier, rigid plastic model. The problem i worry about is how we can do a plastic model if only < 50 people buy it. If it's priced at, say, $45, more than the desktop kit, you know, we might expect less volume and be able to do a small run... but I dunno. Could we do a laser-cut plastic version as a backup plan if we don't get enough orders?

2) A fancy "countertop" model which comes with a prebuilt stand and testing dish, and is "testing ready" for wine, coffee, beer enthusiasts -- the kind of thing you could actually put in a coffeeshop or wine bar. I've already made a decent version of this, and it'd involve a couple lasercut parts, a dimmable light, and a ready-to-use, precalibrated spectrometer.. I'm thinking $200-250?

Final question -- what $ threshold to go for? With the low end at <$10 but a very attractive option at ~$200, i feel like we could ask 10-15k... but maybe not. I'd hope to do much better than that... but you know, you want to make sure we get there, worst case.

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I'd put an emphasis on getting lots of orders for the mass produced versions that we get a good margin on. Can you split the difference between the cardboard spectrometer and the fancy plastic one-- like get some laser cut out of a more durable material? Styrene is easily glued and laser cut, and can be folded without breaking. You could offer a self assembly and assembled versions.

when I look back at the balloon mapping kits Kickstarter, all the little rewards and expensive rewards (dual camera sets) weren't particularly profitable and took a lot of staff time. in fact, I think making t-shirts and posters and other things lost us money. I'd have better spent my time locking in the price of the balloon kit given all contingencies (it should have been a little higher), and only offering balloons, reels, and balloon kits.

I'd like to see us do more Kickstarters for products and focus very specifically on the one or two products we're offering. If the fancy "countertop" version helps pay for some of your development time (like the dual camera sets did) then it's worth it. if it merely takes up your time with assembly, then it's not. If that means only offering two products-- a portable and a desktop spectrometer, then I don't think that's a bad thing.

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I like the direction the rewards are going. The "whole shooting match" might be unnecessary. If someone wants two spectrometers, can't they just back the campaign twice? Maybe fill that price gap with a ready-to-use desktop spectrometer for around $100? But I still have a rather vague idea about what each reward is (assembled vs kit, desktop vs countertop).

I like Mathew's idea of emphasizing that you did the hard design and calibration of a clever and elegant system and now you need backers' help to refine the protocols and find the best uses for the tool. I think people will respond strongly to the idea that they can own their first spectrometer which is a cutting edge tool with precision measured in NANOMETERS! But the video images make the spectrometer look a little ratty. The torn pieces of tape on the webcam and the broken piece of DVD do not match the perception that this is a clever and elegant high-tech system. Those details should be interpreted as evidence of brilliant hacking, but they might instead weaken people's confidence in the tool. We know that diffraction does not care about ratty tape, but that is a sophisticated understanding.

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OK great feedback. I'm going to narrow the rewards to 3 which are announced in the video, and the 4th paper cutout one will still be offered but less emphasized. I de-rattified the webcam grating:

And here's a reworking of parts of the script (i have yet to integrate it with the existing script):

Ever since we made it easy to make your own balloon maps during the Gulf oil spill, we in the Public Lab community have been working on new ways to detect, quantify, and investigate environmental contamination. We want to be able to prove whether a given patch of brown goo is in fact crude, motor oil, or just mud.

(... explanation of spectrometry, short)

We've taken the same open source, collaborative approach as we did in balloon mapping, and over the past year we've solved 3 key problems:

  • We've developed a reliable, cheap design with excellent precision
  • We've created open source software for calibrating instruments and collecting standardized data
  • We've made a shared online database and toolkit for analyzing, comparing, and exchanging datasets

Now we need your help. To build an open-source library of spectra, Wikipedia-style, we need your participation in collecting and analyzing new data. This will make new things possible, like spectral matching -- imagine SHAZAM for materials.

(clip of mobile spectrometer matching)

To get started, we're offering an easy-to-assemble kit...

For the adventuresome, we're also offering an experimental "mobile spectrometer" attachment for smartphones.

Finally, for those of you who want to do a lot of testing -- at a coffee shop, or a wine bar -- we're offering a special "countertop" model which comes with Pyrex sample dishes, a stand, and an adjustable halogen lamp.

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OK, the script/video is still evolving but coming together. Here's the text description which will be shown on (unfortunately stripped of links, copy-paste didn't preserve them):

A spectrometer may not sound like what you wanted for your birthday, but it's a ubiquitous tool for scientists to identify unknown materials, like oil spill residue or coal tar in urban waterways. But they cost thousands of dollars and are hard to use -- so we've designed our own.

This open hardware kit costs only $35, but has a range of more than 400-900 nanometers, and a resolution of as high as 3 nm. A spectrometer is essentially a tool to measure the colors absorbed by a material. You can construct this one yourself from a piece of a DVD-R, black paper, a VHS box, and an HD USB webcam.

We've also created open source software ( to collect, analyze, compare, and share calibrated spectral data. We've even made an experimental version which converts your cellphone into a spectrometer (see rewards)!

Public Lab community members have used this new tool to identify dyes in "free and clear" laundry detergent, to test grow lamps, and to analyze wines.

Now we need your help in collecting data 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.

Public Lab is an open community (join now!) which investigates environmental issues with DIY tools. You might have heard about our first big project to document the BP oil spill using aerial photos from kites and balloons. Since then we've been working on new ways to ID contamination on the cheap. We hope you'll join us in taking the next step!

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