# Freshman HS student working on a scanning tunneling microscope

#### baconbits423

I am a freshman high school student working on a scanning tunneling microscope for a science fair project. I need to build a vacume for bottom up capabilities. If anyone can help with the STM or the vacume it would be greatly appreciated.

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#### baconbits423

There arent any really demanding time constraints, april or may i would guess. I am hoping to apply for and recieve a grant to cover the cost, if you have any suggestions f where to apply.

#### Gokul43201

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I hope you have the design and cost analysis worked out (do you have any source that told you this was possible). I can't imagine building an ambient (no or low-vacuum) low-end STM for less than $1000 (probably will come closer to$2000 - much more if you want medium to high vacuum), and I don't think it can be done over 4-5 months unless you're got lots and lots of spare time.

And in addition to all this, there's the whole knowledge thingy. You'd better be pretty good at designing and debugging electronics (pre-amps, ADCs, etc.) and writing data acquisition codes (unless there's something out there that you can steal). The vibration isolation is far from trivial - you need to know a good bit of vibration theory.

I'd say this project is far beyond the scope of the typical high-school freshman. I'm not trying to discourage you, because I don't really know anything about you to make a specific judgement, but this is my honest opinion.

#### ZapperZ

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I tend to agree with Gokul. The whole reason to build an STM is the fine resolution that one can achieve with the atomic-scale tip. To be able to do that, one then needs a lot of things: ultra-high vacuum, vibration isolation, electrical/thermal isolation, etc... These are neither cheap nor easy to do.

If you want to simply build a "bad" STM, then you might as well simply build a generic tunneling junction, since all the ability of an STM will be washed out.

Zz.

#### baconbits423

It is not necessary to have a vacume just for normal scanning with a stm. A vacume would only be required for bottom up capabilities or to reduce oxidation of the tungsten tips if that is what you choose to use. As for the electronics i have a bit of expirence and outside of school i have lots of spare time, and the project doesnt necessarily have to be done in a few months, i will be continuing this project for a few years making improvements each year.

#### baconbits423

I have noticed all of the people who have viewed the post, please if you have the time please respond.

Thanks

#### cesiumfrog

I have noticed all of the people who have viewed the post, please if you have the time please respond.
Well, since you asked, I also fail to see any point in trying to make something that really won't work. Why not devote the energy to something that you can make work well, given your resources. There exists no shortage of interesting projects you could build (though I won't bother listing those that I am interested in, I'm sure there are other projects, or stepping-projects, that you could become even more enthusiastic about).

#### baconbits423

what other projects can you think of?

#### baconbits423

Why wont my stm project work well by the way??

#### Gokul43201

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Baconbits: do you know of anyone that has built an STM with the capabilities that you envision, within the budget and time limit that you've got?

#### baconbits423

Not someone who has built one but i am working in cooperation with a professor at umsl center for molecular electronics and he has done something similar, and for now i only need to be able to see with atomic resolution.