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Stanford bioengineer develops a 50-cent paper microscope

Stanford bioengineer develops a 50-cent paper microscope

Updated 9.17.14: For his work, Prakash has been named one of Popular Science magazine’s “Brilliant 10” for 2014. He was also recently included in Technology Review’s list of 35 innovators under 35 (Prakash is 34).


Updated 6.18.14:Prakash demonstrated his invention at the first-ever White House Maker Faire this week. A paper further describing Foldscope was also published online in PLOS One.


Updated 3.14.14: A second blog entry, including a link to Prakash’s TED talk on this topic, can be found here. And this entry discusses Prakash’s plans to give away 10,000 build-your-own paper microscope kits to citizen scientists with the most inspiring ideas for things to do with this new invention.


3.11.14: When Manu Prakash, PhD, wants to impress lab visitors with the durability of his Origami-based paper microscope, he throws it off a three-story balcony, stomps on it with his foot and dunks it into a water-filled beaker. Miraculously, it still works.

Even more amazing is that this microscope — a bookmark-sized piece of layered cardstock with a micro-lens — only costs about 50 cents in materials to make.

In the video posted above, you can see his “Foldscope” being built in just a few minutes, then used to project giant images of plant tissue on the wall of a dark room.

Prakash’s dream is that this ultra-low-cost microscope will someday be distributed widely to detect dangerous blood-borne diseases like malaria, African sleeping sickness, schistosomiasis and Chagas.

“I wanted to make the best possible disease-detection instrument that we could almost distribute for free,” said Prakash. “What came out of this project is what we call use-and-throw microscopy.”

The Foldscope can be assembled in minutes, includes no mechanical moving parts, packs in a flat configuration, is extremely rugged and can be incinerated after use to safely dispose of infectious biological samples. With minor design modifications, it can be used for bright-field, multi-fluorescence or projection microscopy.

One of the unique design features of the microscope is the use of inexpensive spherical lenses rather than the precision-ground curved glass lenses used in traditional microscopes. These poppy-seed-sized lenses were originally mass produced in various sizes as an abrasive grit that was thrown into industrial tumblers to knock the rough edges off metal parts. In the simplest configuration of the Foldscope, one 17-cent lens is press-fit into a small hole in the center of the slide-mounting platform. Some of his more sophisticated versions use multiple lenses and filters.

To use a Foldscope, a sample is mounted on a microscope slide and wedged between the paper layers of the microscope. With a thumb and forefinger grasping each end of the layered paper strip, a user holds the micro-lens close enough to one eye that eyebrows touch the paper. Focusing and locating a target object are achieved by flexing and sliding the paper platform with the thumb and fingers.


Because of the unique optical physics of a spherical lens held close to the eye, samples can be magnified up to 2,000 times. (To the right are two disease-causing microbes, Giardia lamblia and Leishmania donovani, photographed through a Foldscope.)

The Foldscope can be customized for the detection of specific organisms by adding various combinations of colored LED lights powered by a watch battery, sample stains and fluorescent filters. It can also be configured to project images on the wall of a dark room.

In addition, Prakash is passionate about mass-producing the Foldscope for educational purposes, to inspire children — our future scientists — to explore and learn from the microscopic world.

In a recent Stanford bioengineering course, Prakash used the Foldscope to teach students about the physics of microscopy. He had the entire class build their own Foldscope. Then teams wrote reports on microscopic observations or designed Foldscope accessories, such a smartphone camera attachment.

For more on Foldscope optics, a materials list and construction details, read Prakash’s technical paper.

Previously: Stanford bioengineer developing an “Electric Band-Aid Worm TestStanford bioengineers create an ultra-low-cost oral cancer screening tool,
Related: Prakash wins Gates grant for paper microscope development

33 Responses to “ Stanford bioengineer develops a 50-cent paper microscope ”

  1. wawb Says:

    50 cents to produce. $100 charge to insurance?

  2. Jim Says:

    Any though on posting the design on There’s an international army of makers who would love to try this, modify and share improvements.

  3. Kris Newby Says:

    To sign up for the “10,000 Microscope Project” where Prakash will give away 10,000 build-your-own-Foldscope kits to 10,000 people who pledge to share their experiences and experiments on his website, go here:

  4. Zoe Says:

    How to print it ourselves?!

  5. Brian White Says:

    I have a bunch of friends in the Lyme community. Some of them have videos posted of their spirochetes in live blood. (They come out of red blood cells after about 10 minutes on a slide. I think it needs phase contrast microscopy but not sure. I think several techniques can work. I would be happy to put some of the more frequent youtubers or bloggers in contact with you. I know people 2 minutes walk from me in Canada, elsewhere in Canada and in the UK and the USA with Lyme. Brian

  6. Jeremy Says:

    You can download & print plans from here:

  7. mad.madrasi Says:

    “These poppy-seed-sized lenses *where* originally mass produced” –> didn’t require a Foldscope to spot that ‘where’. Good job though.

  8. Rex Fatahi Says:

    Awesome! Jaw on the floor Awesome! How do you anticipate samples to be processed on a mass scale, how thick are sections, and any plans or chance for visualizing fluorescence/utilizing for research studies? Thank you!

  9. Baxter Says:

    Is there a patent on this?

  10. Ton Says:

    I use an old cd player inner lens mounted before my I phone. Guess what you can do with tha!!!!
    These lensen are everywere (scrap) or in your case can be obtained from the factory ( sponsering?)and I think are a little bit better. See yo soon again at TED??

    Good idea anyhow.

  11. zachary Says:

    Love this. Thanks for being a genius.

  12. John Says:

    Those are some awfully optimistic prices on that bill of materials. I’ve never seen a watch battery for 5 cents, anywhere. The whole thing needs to be cut out with a multi-thousand dollar laser cutter. All of the components are not readily available off-the-shelf either. Too much hype. You can, however, find digital USB 2000x microscopes on the web for ~$250.

  13. Alexei Says:

    See Leeuwenhoek. Lens can be prepared by thin glass thread fusing instead of polishing.

  14. Geoff Says:

    @jeremy: The download includes pictures of the plans, but not a fully-printable PDF. Is that available anywhere, please?

  15. Bhupendra Madhiwalla Says:

    I work in scores of villages of Maharashtra, India since last 10 years and even have established two traditional path labs Dist.Raigad for complete blood tests at very low testing cost of Rs.15-Rs.45. I would like to use Foldscope in the fieldwork.

    Warm regards

  16. Martin Hunt Says:

    I am fascinated by this idea but I wonder how the lenses are made and positioned in the sheet that becomes the microscope

  17. Rama Says:

    Hi Manu,
    I am a parent from India and am really interested in this instrument to get them initiated into the world of Biology. Where can I buy this instrument? Any online shop would be great.

    Thanks and regards,


  18. William Hughes-Games Says:

    In an item on New Zealand Radio on the Fold Scope, the inventor mentioned that they need funding to make these FoldScopes in quantity. Easy-Peazy. Sell them to the first world for $10 each. Say, up front, that even though the scope costs $1 to make and $1 to ship, we are charging you $10 so we can make more of these for the third world. I bet the response would be overwhelming.

  19. William Hughes-Games Says:

    Can I be very cheeky and suggest a slight improvement to the design. Watch batteries are a pain to find in many places and as far as I know, there are no rechargeable versions. Redesign the scope to use a simple ubiquitous triple A battery. They are easy to find anywhere and rechargeable versions exist which in the long run are far cheaper and don’t produce as much waste as the throw away versions.

  20. john Says:

    William ,I’ll send ya $10.00 bucks,sign me up


    I’d like to ask, is it only papers folded on each others? or there is a lense, well, there is a lense, so, how much magnification of that lense? is it only an objective lense? well, how much is its power of magnification? or there is also a subjective lense? if so, please , describe your theory of this light reflection and magnification process.
    Thank you

  22. Joe Gubler Says:

    I would love it if someone would contact me on where I can purchase a large amount of these to donate to my daughters school district and also to send to Haiti.

  23. Claude Says:

    If you want a truly long term viable power source for the device that can also be easy recharged from ambient resources. I would suggest you contact Cymbet Corporation and discuss the use of their Enerchip line. Far friendly to the environment than the standard lithium coin battery

  24. John Says:

    This has potential for field research. Screening for hot spots or verifying algae content would be the great. The plans seem to be in the PDF but the resolution of the image for the microscope seems to be low. All in all a great project. Science on a shoestring budget, something we in science will have to pay attention to more.

  25. Mandy Erwin Says:

    Good morning! I would love to purchase some of these for my kids’ elementary school. We also would love to send some to one of our sister schools in another country. We are an International Baccalaureate World school ( and have a big science and inquiry fair coming. I don’t know if you are selling them yet, but I would love to share this with our school and others. Thank you and wow!

  26. Dr. Dion N. Johnson Says:

    I am assisting a K-12 community school with creating a STEAM Innovation & Knowledge HUB, as they are trying to move their Common Core Curriculum into a STEM to STEAM driven program. It would be great to receive several Foldscopes or able to purchase. Please contact me ASAP. Congratulations on a great new support product and great innovation. Thank you, smile.

  27. Douglas W. Rick Says:

    Congratulations Dr. Prakash!

    As a child of 10 I got my 1st little microscope and later (age 15) I was lucky enough to be given a Zeiss microscope from a retired Pathologist friend of my parents. When she was in Medical School (before WWII), students were required to purchase their own microscope for use in their training and, in near perfect condition and in its original carrying case, she gave it to me. I spent many countless hours exploring the otherwise invisable world around me. After working as a Med Tech for several years, I went to work for the Coulter Coprporation (now Beckman Coulter) and later at the Coulter Biomedical Research Corporation in Concord MA. where Coulter developed a very sophisticated pattern recognition system using a video camera, ccd and software to automate the otherwise tedious microscopic examination of peripheral blood smears, LE prep, pap smears, etc. The system was unique in that recorded the coordinates of every cell it identified and included a standard microscope (Zeiss lenses, again) which gave the operator the ability to visually verify any cell microscopically. Now, I have just learned of your truly amazing invention and, although I am now retired, I would love to get one of your Foldscopes (or many to give as gifts) to explore possible applications. Like the first Coulter Counter, this little devise is bound to have a major impact on disease detection and treatment.

    Keep going, Doug

  28. F. Haggerty Says:

    As I am sure you’ve heard, the applications are endless. Everything from saving lives to saving children’s imagination. As I child I wish we could have afforded a microscope or even our school had one for all the things I wanted to see. It is a fantastic tool for all the wonders that can wonder. I look forward to the day I can get one to share. Thanks to you and your students.

  29. eein Says:

    Yes there is a patent.

    Anyone interested in the foldscopes can apply still at
    Please propose what you will do with them.

    -assistant to Manu Prakash

  30. Marie Noel Says:

    4 of us have tried to sign up for the free foldscope and receive more information and have not been successful- the email we have returns.Please contact us.

  31. Frank Neu Says:

    If you add an image sensor so the magnified object can be displayed on a computer screen, it would help. The image of interest could then be captured and stored. Those who want that feature would be willing to pay more for that kind of foldscope.

  32. Meghan Medina Says:

    I’m fascinated with this notion but My spouse and i ponder how a contacts are designed in addition to positioned in the actual published in which will become the actual microscope.

  33. Mahbub Says:

    Great & amazing …I wonder …can you send me or where i found it in my country.
    Thank to all people who made it…..


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