DIY Scanning Electron Microscope - Overview

Today, I finally produced an image with my DIY scanning electron microscope. I've spent the last few months working on this project, and am encouraged by today's success. There is still a lot of work left to do in making the image higher resolution, and eliminating sources of noise, however this image proves that all parts of the microscope are operating as designed.

I will be showing this project at Maker Faire 2011 in San Mateo. Come see it for yourself in person!

http://benkrasnow.blogspot.com/2011/03/diy-scanning-electron-microscope.html

Search my blog for "microscope" for additional images and info:
http://benkrasnow.blogspot.com/

Category:

Science & Technology

Tags:

• SEM
• scanning electron microscope
• microscope
• electron
• beam
• DIY

[Nomoreidsleft]

Great explanation! Btw, what are all those spark plugs used for?

[bkraz333]

@Nomoreidsleft They are just high voltage insulators that allow high voltage to be passed into the vacuum chamber. I soldered directly to the spark plug center electrode.

[UKLifeCoaching]

Fantastic - congratulations. I'd love to see some more images when you get things refined.

[bkraz333]

@UKLifeCoaching Thanks! check out my blog for more images -- link in the description.  Search the blog for "microscope" to see all related posts. I'll also make another video showing microscope operation after all of the changes that I have made to the device.

[lilbahr]

A question: Would the quality of the vacuum increase compared to plain air in equivalent pressures if the dome was first filled with helium and then the vacuum pump was used?

[bkraz333]

@lilbahr Commercial SEMs often fill the chamber with dry nitrogen instead of venting it to the atmosphere. This avoids sucking lots of humid air into the chamber where water molecules can stick to exposed surfaces. Filling with He would have a similar effect. I believe pumping speed for He is higher than air, so the chamber should reach ultimate pressure more quickly, but the biggest benefit is avoiding atmospheric water.

[bkraz333]

@gemis94 Yes, good question. I initially used Teflon-insulated stranded wire, but found some problems. Even though Teflon is rated for high vacuum use, the insulation still outgasses more than the bare metal, so using uninsulated wire is better for maintaining a high vacuum. Additionally, the wire insulation can become charged if stray electrons crash into it. Overtime, the charge can build up high enough in the insulator to cause a breakdown. I saw this happen many times.

[wa4aos]

Excellent video and well explained.

[rplcmint]

Good Job. You need to give a lecture at the San Joaquin Delta College Electron Microscopy Program in Stockton about your ideas. Student microscopists can learn a lot from your SEM creation!!

[hellioio]

U just upgraded from electronics to Quantum mechanics!!!! Good luck dont go there

[Bellefeuille66]

Didnt understand 99% of this video..got to go watch jersey shore so I feel smart again now!

[anthonyj777]

Got here from the Amp Hour, how did I not know about your videos before? Top stuff all together! Loving this series, great explanation :)

[nathanspallone]

Looks like what you have now is a scanning electron spectroscopy tool. Without a few improvements, your microscopy will be limited. You should add several stages of positive electrical field lenses for refinement. You aught to get a better pump, like a turbomolecular pump for second-stage pump down. You need to bake out (heat up) your chamber to dislodge 'stuck' air particles from all components in the chamber. I work with a condensed matter research group, if you want advice, I'm here.

[uzinder]

Converting electrons into photons just to convert them into electrons again seems a bit complicated.

[menushadesanayaka255]

sUPER PROject!

how much time and money was spent on this project?

[outdozstore]

It's amazing you can do that !!!!!