Cheap microscopes: Yours to cut out and keep(economist.com)

340 pointsby feelthepain12 lat temu56 comments

Cheap microscopes: Yours to cut out and keep

http://www.economist.com/blogs/babbage/2014/04/cheap-microscopes

14 comments

I think it is a great product, but the numbers are a little misleading. In microscopy the most important number is usually the resolution not the magnification, and 1µm is what you expect from a 20x objective. The 2100x specification doesn't help much and confuses people, but to be fair, a good 20x objective starts in the $200-400 range.

EpicEng12 lat temu

I work on digital microscope scanners and I have always thought that 1um was the general value for a 10x objective (because that is always what it is on scanners.), 0.5um for 20x, etc. I realize that many factors contribute to effective magnification (and resolution), but your statement makes me want to look more closely at standard microscopes.

chrisBob12 lat temu

The resolution is given by 1.22λ/NA.

λ can be rounded to 500nm and the NA of a standard 20x objective is .4 giving 1.5µm. This is good because I was worried you caught me just making things up for the internet. A 40x with a .65 NA gives just under 1µm resolution.

Resolution is also a slightly fuzzy spec depending on the audience. I go with the Raleigh criteria: You can't distinguish between two particles separated by less than the resolution distance. You can however, see particles much smaller than that, and there are many variations, most of which give you better resolution numbers. We occasionally use other specifications when we need to say we met a specific target.

The standard objectives I am quoting are Olympus Plan Acromats, different systems have different tube lenses which cause you to get a different magnification out of the same objective. That is why the NA is the important factor. Otherwise I would just use a 1m tube lens and get 5x higher magnification numbers to report similar to what we see with the paper microscope.

EpicEng12 lat temu

Ok, that makes sense. We tend to use high NA objectives for our applications, and the light path is a bit longer than in standard scopes (though not too long as to introduce too much empty magnification.) shows how much I still have to learn about optical systems even though I've been writing control sofwtware for these things for almost five years now.

gcb012 lat temu

plus, it currently costs thousands per prototype. the $1 is a best guess.

chillingeffect12 lat temu

When I was a kid, I got a similar toy in a Happy Meal [0]. It was a hunk of yellow plastic with a little lens. This is the time same thing, except with a better lens and an LED, so I think $1 is maybe on the high side.

[0] http://www.complex.com/city-guide/2012/01/the-50-coolest-hap...

dm212 lat temu

I found this DIY microscope for smartphones if anyone is interested: http://www.instructables.com/id/10-Smartphone-to-digital-mic...

Lambdanaut12 lat temu

I saw this in action at a local maker faire. It uses a laser pointer's lens as the refractor, and works pretty well! Definitely a clever hack, and the bonus is you can easily take pictures of what you find!

zafka12 lat temu

I did a quick search on the glass spheres, and the only place I could find to buy them was Edmund Optics for $15.00 each. Does anyone have a decent source for the lenses?

chrisBob12 lat temu

Edmund has good prices. That is probably your best bet in small quantities. One of the nice things about ball lenses is that they are made in batches, so large orders scale well.

mkl12 lat temu

Try http://alibaba.com or http://aliexpress.com:

http://www.alibaba.com/product-detail/borosilicate-glass-bea...

http://www.aliexpress.com/item/Borosilicate-Glass-Beads/5255...

http://www.aliexpress.com/item/Borosilicate-Glass-Balls/5255...

That last one says US $0.11 / piece. It's hard to tell how well these would work as lenses though.

dm212 lat temu

I'm not sure if these are the same but I found this: http://www.aixiz.com/store/product_info.php/cPath/46/product...

gradi3nt12 lat temu

Can anyone comment on the more technical optical properties of this instrument? How does it perform compared to a traditional microscope with the same magnification and resolution?

twistedpair12 lat temu

I'm a dev, but got my degree in optical engineering not that long ago.

The reason this is not news is that good microscopes cost money. Saying "hey, I've achieved 2100x magnication!" is pretty meaningless. Anyone who's ever used a nice camera can instantly realize the difference in the photos you get with a $500 Canon lens compared to that disposable camera you bought for $5.

The pictures they've supplied are wonderfully blurry. Three cheers for poor light sources, spherical aberration and diffraction blur. If you're doing slides with results of great import, such as various health tests, you want an accurate image. We don't get to see any shots of optical calibration targets here, which would demonstrate just how poor the optics are. As a rule of thumb, anything over 1000x is usually poor and 1500x is considered the practical limit of optical microscopy (without some really expensive tricks like conjugate points and fluorescence which gets you a $100K+ kit).

So yeah for cheap microscopes!, but I had a $5 one as a kid. Nothing new here. Plus, training people to properly prepare the slides and interpret the images correctly is a far larger problem. I've watch Harvard and other labs haul away truck loads of old equipment to the dumps. Let's send that to anyone in the 3rd world that wants it, but not waste too much time doing what's already been done.

nathancahill12 lat temu

This is based on a ball lens. There are several ball lens hacks floating around the internet, like this "iPhone Microscope" research paper[0] and this DIY[1] to build your own. Ball lenses are cheap and you can attach it to cellphone camera lens with a little M3 tape.

The cutout paper part seems to just hold the slide, and pane it in front of the lens.

[0] http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...

[1] http://www.instructables.com/id/Cheap-and-easy-iPhone-micros...

davexunit12 lat temu

Please tell me that the specifications will be released under a free culture license.

popey12 lat temu

From their FAQ, which to me means "no".

" Is Foldscope an open hardware project? Do you have plans for the same?

We are currently exploring best possible ways to provide quality tools to largest number of people. We have two missions; one in healthcare and one in education. We are exploring all possible options to bring this tool to the masses and exploring licenses that allow us to do this in a sustainable manner. More information about this will be available here soon. "

davexunit12 lat temu

Thanks for that. It's counterproductive for a project like this to not be free/open hardware.

[deleted]12 lat temu

ColinWright12 lat temu

frozenport12 lat temu

You can get a children's microscope for $5 dollars that has the same resolving power, but it still hasn't changed healthcare.

I got tired arguing with people that the cost of healthcare is not the microscope.

Its either the people or the disposable goods. For example, it is difficult and costly to prepare the following slides: http://cdn.dogomedia.com/system/ckeditor_assets/pictures/532...

At the end of the day $757,000 could have been used to dig 1000 wells.

vacri12 lat temu

I remember seeing a talk by an antarctic scientist researching anti-freeze oils in fish, for use in the food sciences. Down there with his crew and expensive equipment, boring a hole through the ice to catch fish... and the most fundamental bit of equipment they used in the process was the fishing rod. They couldn't find a short rod easily (Australian, no culture of ice fishing) so they ended up using a toy Snoopy-branded rod, all of about 30 cm long...

foobarian12 lat temu

Why on Earth did they happen to bring a toy Snoopy-branded fishing rod with them on an Antarctic expedition?

vacri12 lat temu

It was purchased as part of the mission equipment. Australia doesn't have ice fishing, so there aren't really any sources for short fishing rods. The toy rod was available, and did the job!

dang12 lat temu

Thanks Colin. Normally, the fact that this story had a significant discussion within the last year would cause us to bury the post as a dupe. However, let's make an exception in this worthy case.

cheetahtech12 lat temu

Here is the Ted Talk on the Microscope.

Its quite incredible.

http://www.ted.com/talks/manu_prakash_a_50_cent_microscope_t...

gcb012 lat temu

So it is a lens, CR232 batteries, and a LED... and you are invited to use and throw it away with the battery? not very clever.

dhaivatpandya12 lat temu

I think this comment exemplifies the "HN negativity syndrome".

Completely disregarding the years of effort poured into developing a paper lens, etc., you simply dump the innovation into the "not very clever" pile?

gcb012 lat temu

paper lens?! are you trying to signify the other side of HN that upvotes kickstarter links without even reading? :D

dhaivatpandya12 lat temu

See research paper: http://arxiv.org/abs/1403.1211

When I said "paper lens", I meant the idea of embedding the lens into the paper.

tedsanders12 lat temu

The battery is optional (slides can be backlit by holding the foldscope up to a room light or even the sun).

Throwing it away is optional (these foldscopes are quite durable).

I think your criticism can be applied to any consumer good, since all consumer goods eventually end up being thrown away.

userbinator12 lat temu

Did you mean s/clever/environmentally friendly/ ?

RankingMember12 lat temu

Wow, this is awesome. I've been looking for a cheap microscope to just have around the house and noticed that they indeed haven't changed a lot in cost/features in quite some time.

VLM12 lat temu

Note that this is a different meme than the popular "you can make your own working general purpose camera out of cardboard". That meme is moderately popular and has been successfully implemented many times.

This is a different concept, of a precision manufactured, very cheap, single use, very specific medical test microscope generally revolving around a projection display technology.

I'm not saying its not cool. It is cool and is a net gain to humanity etc. Its just probably not what you're thinking it is based on the short description.

I think a general purpose "print/fold at home" microscope for educational purposes would be interesting, along the lines of numerous successful cardboard photographic cameras, and maybe even useful. The linked article, although also cool, has nothing to do with that meme, and is almost the precise opposite other than common construction material.

Also this is an old story, even if newly reported. I remember watching the TED talk from the TED RSS feed during a blizzard some months ago. As per Colin's post this is the 12th time its been featured on HN.

pcl12 lat temu

The article didn't mention anything about it being a single-use device. And from the description, it sounds like the intention is that the device would be printed professionally for best results, but assembled by anyone (hence the focus in simple instructions that don't require any test).

Also, the article mentions projection capabilities, but as a non-standard modification.

VLM12 lat temu

Watch the TED talk from a couple months ago, it was pretty good, better than the average ted talk and I mean that as a compliment to the presenter not as trashing the rest of ted, or read the other 12 HN postings, I am correct in those assertions, at least as presented.

dm212 lat temu

How do I purchase one?

Is it possible to attach to a phone to take a picture?

Here is their website: http://www.foldscope.com/

Why would the initial test to 10,000 if it only costs $1. I would gladly pay $5 (if that includes shipping). If there is a version 2, I would gladly pay $5 to purchase that one also.

This reminds me of the Cartmanland commercial, "awesome new themepark, and you can't come!"

paulgerhardt12 lat temu

If you're ever in China you can pick up cheap microscopes for $2-$4 with 50-150x magnification that fit to your phone's camera with a special case.

They are absolutely wonderful for factory inspections.[1]

I have a few but my preferred model looks like this: http://item.taobao.com/item.htm?spm=a230r.1.14.80.ScwWS1&id=...

Desktop microscopes with HDMI out, 5" monitor, and 500x zoom can be picked up for about $80

[1] http://instagram.com/p/eRjdQiNIOi/

SiVal12 lat temu

If you're ever in China you can pick up cheap microscopes

Where exactly? I might want to check them out...

paulgerhardt12 lat temu

That Taobao link above is good start. Taobao is incredible.

That said, if you're not set up with local bank account and mailing address one can find them in any electronics market.

SEG Plaza in Shenzhen or Modern Electronic City in Shanghai should have them for 20 kuai.

They usually come with an ultraviolet led for currency fraud detection - there are so many small stores and so many people in China that these are basically ubiquitous.

There is a trickle down effect on Amazon too: http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3D... - see for instance the one available for $3.96 - I would splurge and get the square boxy one though.

waps12 lat temu

Presumably it's things like this :

http://www.dx.com/p/60x-zoom-led-micro-lens-microscope-w-bac...

Aardwolf12 lat temu

I wonder if it's also possible to make it yourself from paper?

Or 3D print it?

Not that the makers don't deserve the money!

yitchelle12 lat temu

Maybe not from paper, but the research paper is here[1], so no obstacles. Right? :-)

[1] - http://arxiv.org/ftp/arxiv/papers/1403/1403.1211.pdf

Steuard12 lat temu

Side note (as a scientist who uses the site): there are lots of different ways to share an arXiv.org link, but in almost every case the best option is this:

http://arxiv.org/abs/1403.1211

That links to an abstract page for the same paper you linked to rather than the full PDF, and it's a lot shorter to type (and less specific about format). This form often avoids accidentally linking to an outdated version of the file, too.

dm212 lat temu

I think there are a couple components that can't be printed such as the lens and the optional LED.

tmikaeld12 lat temu

Short answer: You can't!

From the FAQ:

"Foldscope is not yet commercially available. Foldscope is a project out of Prakash Lab, a research group in the Department of Bioengineering at Stanford University. We are working hard to make the microscopes commercially available via a spinoff/startup while keeping the mission and our goal aligned to the big vision from our viewpoint. More details of the same will be posted here at some point."

netcraft12 lat temu

I wish that had a date, and some information about when it might be commercially available.

Tenoke12 lat temu

I wouldn't hold my breath. In pretty much all articles I've read over the last few years they always leave the impression that it would be available fairly soon, however, no product gets released.

I am actually very surprised that people still get this excited over the same piece of news.

baldfat12 lat temu

My Brother In-law wife and three kids are moving to Zambia for 5 years. This would really help out the medical part of their mission, as well as digging wells.

dsfadadsffd12 lat temu

not happening

neals12 lat temu

Are there any images of what a 2100x magnification looks like?

neals12 lat temu

I found this page that shows various levels of magnification: http://www.grayfieldoptical.com/selected-examples-1.html

chrisBob12 lat temu

This is exactly why the 2100x spec is a bad one. The 1µm resolution they claim is no where near as good as the resolution in the linked 2000x images here.

netcraft12 lat temu

Did anyone get in the initial test that can comment on the quality and performance?

tedsanders12 lat temu

Yes. What would you like to know? The devices are cheap and durable and they work.

netcraft12 lat temu

Do you have any pictures of the whole device? What is the overall size? How long does the watch battery last? I would assume quite a while since it is an LED

tedsanders12 lat temu

It's like 6" by 3" by 1/4".

You can see the size in the TED talk or on the website: http://www.foldscope.com/#/scienceeducation/

Honestly, I'm not sure how long the battery lasts. I've mostly worked with the versions that have no backlight (to use them, you hold them up to a lightbulb or to the sun).