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Make: Live ep03 video is online! Thanks to our guest Sean Ragan, we enjoyed an evening of science.

Subscribe to the MAKE Podcast in iTunes, download Make: Live episode 03 in its entirety (m4v), or watch clips on YouTube. Also check out the chat room transcript!

Sean Ragan – Laser Projection Microscope
MAKE contributing writer and organic chemist Sean Ragan joins us via Skype to show us his homebrew microscope which uses a bright laser to project an image through a droplet of water – microbial movie theater! Learn to build your own laser projection microscope on Make: Projects.

Electrochemistry demo from the Illustrated Guide to Home Chemistry Experiments

Becky dons her lab coat to demonstrate the production of hydrogen and oxygen by electrolysis of water (with the help of a 9V battery). You can tell the difference between the two gases with a lit match – FWOOM! This lab appears in chapter 16 of our own Illustrated Guide to Home Chemistry Experiments by Robert Bruce Thompson.

Show notes:

Becky Stern

Becky Stern is head of wearable electronics at Adafruit Industries. Her personal site: sternlab.org


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Comments

  1. Matt Wallace says:

    So how about a link to that article? I’m super curious as to mods/hacks that could make this even neater. I wonder whether the limiting factor here is really the droplet “lens”. I wonder also if that could be tweaked by altering the shape of the lens and/or it’s refractive index by changing the composition of the sample solution…

    1. Becky Stern says:

      There’s a link to the tutorial on Make: Projects. The microscope hasn’t appeared in the print mag.

    2. I believe Matt is referring to the 2001 journal article I mentioned
      on-air last night as the earliest publication of the idea that I know
      of. That article is:

      “Water-drop projector,” Gorazd Planinsic, Phys. Teach. 39, 76 (2001), DOI:10.1119/1.1355162

      It is freely available at:

      http://www.fmf.uni-lj.si/~planinsic/physteac/physteac_gp.pdf

      The formula for calculating the magnification of the projector appears on p. 20.

      I have added this information to the tutorial on Make: Projects.

      Thanks for the reminder!

      1. Becky Stern says:

        Good call! Thanks Sean.

    3. I believe Matt is referring to the 2001journal article I mentioned
      on-air last night as the earliest publication of the idea that I know
      if. That article is:

      “Water-drop projector”
      Gorazd Planinsic, Phys. Teach. 39, 76 (2001), DOI:10.1119/1.1355162

      It is freely available at:

      http://www.fmf.uni-lj.si/~planinsic/physteac/physteac_gp.pdf

      The article is:

      Water-Drop Projector,
      THE PHYSICS TEACHER Vol. 39, February 2001

      The formula for calculating the magnification of the projector appears on p. 20.

      I have added this information to the tutorial on Make: Projects.

      Thanks for the reminder!

  2. Andrew Wilds says:

    FYI on the use of green lasers in this project.  The human eye is most sensitive to green light thus using a green laser should yield higher contrast (better contrast means you’re able to identify more detail from the light source) than you would get out of a comparable red or blue laser.  Additional note on lasers exceeding 5 mW, be very careful, lasers above this threshold are classified as Class 3b and can cause permanent damage on short timescale without a properly diffuse (large) projection.  Avoid reflections off of shiny surfaces when possible.