Electron Microscopy (TEM and SEM)
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- čas přidán 2. 02. 2021
- We've talked a lot about light microscopy, but this technique has inherent limitations in resolution and magnification. The next paradigm in microscopy that emerged in the middle of the 20th century was electron microscopy. Because electrons have much shorter wavelengths than photons, electron microscopy offers up to 1,000 times better resolution than light microscopy. This allowed us to visualize structures as small as individual proteins for the first time, which revolutionized the field of biology. What are the types of electron microscopy and how do they work? What can we do with them? Let's learn about transmission electron microscopy and scanning electron microscopy now.
Script by Kia Mackey
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Had an opportunity to work on an Jeol JSM-6010LA SEM for a year (got to analyse some plastics and corroded metals). Absolutely awesome piece of equipment.
I'd add two things, more as curiosities.
1. The X-ray detector in SEMs is there to provide data on elemental composition of material so you can make a map of, for example, oxygen/carbon/nitrogen etc distribution/content.
2. The reason why they require qualified personnel is mainly because they're destructive and in many cases you have only a few minutes (sometimes seconds) before the sample is too irradiated/charged/melted to work with. Also, they're very susceptible to dust contamination (metallic can even affect the electromagnetic lens system) so preparing samples and changing the filament (electron source) is a pain - and the cheap filaments (tungsten, about 50€ a piece for the one I worked with) rarely last more than 50-70 hours.
Find any Covids?
I am applying to work on SEM please can you give me your best advice for the application to be accepted for interview? And why you stopped working with it?
Many thanks!
@@manahilkadhim9934 Unfortunately I can't help you much with that. During my phd studies I was assigned to help with setting up a freshly established lab after one of our post-docs left. Essentially, after preparing training material for the students (samples, instructions and such, including ~20h of uncut footage from SEM, AFM and XRD), I helped as an auxiliary operator/instructor/teacher for a year. After things settled I simply returned to my primary responsibilities.
@@jimmynoname9884 Hello Jimmy, thank you for your response.
@@manahilkadhim9934 Oh, one thing came to my mind: EM labs are often specialized towards either materials science (some specialize only in metallurgy) or biological materials. So from starters they might be looking for people who have experience with analyzing/preparing samples from these. It might be good if you emphasize the types of materials you're experienced with. Also, do check what equipment they have. Modern (post ~2005) EMs are highly software-assisted and thus easier to use, while older equipment requires a lot more theoretical knowledge, so they will most likely prefer people with specialized/physics degrees.
good luck
Electron microscopy is fascinating. It is amazing that we can see so much detail of such tiny things.
Will i finally be able to see my... my.....
@@cutmarkkink
Holi
@@cutmarkkink now now let’s stay realistic 😊
You should see it in action! I work with these things and they are quite fascinating to calibrate.
I've only had the chance to use scanning electron microscopy once, and I didn't really understand what I was doing. I did, however, appreciate the glorious 3-D image it produced of a colony of viruses. Enjoyed this segment, Professor Dave. Keep up the great work!
Why does the CZcams algorithm want me to be a biochemist so bad lol?
Maybe ur destiny wants to meet up with a biochemist
😂😂
Well I can see you should be done by now
So how about you be my mentor
I Persue chemical science and technology do the biological aspect of my course troubles me a bit
Would love to hear your response
I’m okay if you won’t be able to help out
Have a great day 😊
Apparantly you're 3 years too late 😢 @@SaeedWunnam
Your work has helped me a lot on my research of an essay of Physics but also opened curiosity on me about the electron microscopy, thank you so much!
FINALLY!!! After all this time... I understand TEM and SEM...
Thank you Prof. Dave!!
You are my life saver. I need to do an oral on the history of microscope in 3 days. You just saved my life
Thank you! My biology teacher sent this to our biology group for us to watch for extra information :)
Thanks for the helpful tutorial on SEM images. As someone who's interested in this field, I found it really informative.
Thank you professor Dave you are one of my most admired professor
A really detailed explanation. you've explained it wonderfully!
Thanks for the great video prof. Dave
Morn'n Dave, thanks for the lesson!
as always very informative 🤯 Thanks prof 💪
Thank you Dave for this epic critique and tutorial on electron microscope‘s!
Hopefully in the future, you could make an episode explaining how scientist discovered Quarks, Leptons and Gluons? Seeing how they cannot be detected in an electron microscope.
wow!!!
Thank you so much dave 👍
Thank you very much. Your video helps me to prepare for my upcoming interview.
i wish you could teach us also dentistry concepts..
there is no video on this planet more rich than that of yours
Great video! Thank you!
Thank you, that was so useful.
Love this dave
very helpful video professor Dave
Thanks a lot, your videos really help
Sir u explain a very good manner ❤ seriously I understood very well 😊 nd today is my exam of BSC biotech 3 Rd yr nd it's really helpful 4 me ❤ thank you so much sir 😊
Out of curiosity, is this series also going to cover things like atomic-force microscopy?
Great! You are genius… I wish I could know as much as you do
Thank you, thank you!🙏
Thanks prof
Fascinating.
Thank you ❤
Nice work thank U 😍😍
Thank you professor....
Dear sir... Plz upload mix well wave equation of light...
Oh my God.......jinx.....we just did the electron microscope this week😄✨
Very helpful thank so much
Clear explain 💯
Professor, you should make a series on debunking common science myths and pseudoscience. A huge fan of your content,sir🙂
check my debunking playlist, there's a lot in there already and more to come!
@@ProfessorDaveExplains Its just frustrating to see spiritual gurus spread pseudoscience and make a fool out of people to make their living. Some of them in my country been saying we shouldn't sleep north because the earth's magnetic field pulls the iron in our blood to the brain that might lead to hemorrhage 🤣🤣
@@PrajwalSedainOnly a very few are true spiritual gurus.
thank you for the nice video. However it wasn't explained why in TEM the sample needs to be stained with heavy metals?? Could you explain? Thanks.
A nice summary. It would be nice to make the videos a bit longer and to go in a bit more detail.
3D SEM like images can be aquired using the STEM option on a TEM.
Another nice option is tomography. With this option, a set of images is taken. Every image is taken with a different angle of the sample holder, creating a 3d like end result.
The spots on the fluorescence screen that you show are created when the TEM is in "diffraction" mode. In normal imaging mode the fluorescence screen just shows the magnified image of the sample. By lifting the fluorescence screen the "light" (in TEM terms, the electron beam is called light) falls onto the installed camera, and the image can be viewed on the computer screen.
As optic lenses are not perfect, also lenses in an electron microscope suffer from lens abberations. These days, modern tems can be equipped with abberation correctors resulting in spectacular resolutions.
A trade off is often resolution vs destruction. For some samples a high energetic beam can destruct the structure (especially in biological samples), so a less energetic beam is desired. But the higher the energy (more keV), the shorter the wave length, the higher the resolution.
The generated x-rays in a TEM (occur from the interaction of the sample with the electrons) can be used for material analysis.
Watching this video, but commenting on your "debate" with Jesse Peterson. Holy hell, that was painful, and you showed the patience of... well,... the most patient of people. Just had to congratulate you on how you handled yourself in the face of such a dishonest clod. And whoever those people were asking superchat questions... not any smarter than Jesse.
"My ancestors were not slaves"
Sorry, you reminded me of that absolutely hilarious moment.
@@scptime1188 Yup. His ancestors voluntarily respected and worked for powerful, white, Christian men.
So could it be theoretically possible to build an electron microscope using some of the components from a couple of old CRT televisions (or dare I say a microwave or two) for the electron beam/s.?
Hi Professor Dave Explains,
I have question about characterize nano material
1/ Could SEM see nano materials, clearly or blur ? (I mean it's a normal SEM, not FE-SEM or high resolution SEM)
2/ Which is the best method, cheap and convenience for characterizing (shape and size) nano materials?
I hope I would receive your answer soon.
Thanks Professor Dave Explains so much.
Yes SEM can see nanomaterials
none of the too are cheap nor convenient. Shape can only be determined using the backscattered electrons of SEM.
Hope this helps even a year later
@@pressaltf4forfreevbucks179 yup thanks so much
U are a legend
Thanks dude
dễ hiểu, cảm ơn rất nhiều
I can't understand how we can see depth, like how can i tell one point is higher than other on this microscopy. How the electron gives this information?
there are ways to visualize live samples now
Perfect
Electron microscopes are also heavily used in materials physics and the semiconductor industry.
With the help of Electron microscopy scientists can finally find flat earthers brains.
Proof that flat earthers are brain-dead. As the lesson teaches, TEM and SEM cannot be used on live specimens.
Professor 👌
good content! +++
Why do atoms look round in TEM images even though they have different orbital shapes?
I searched Tem hoping to find the animator, but instead i learned about electron microscopes and how they work.
Very well done.. But plzzz speak slowly so that we can eaaily understand
Greatt!
in nanoscience we use TEM every week :D
🔥🔥
I'm guessing the heavy-metal staining and Au/Pd coating of samples applies primarily to biological samples? I haven't come across this sample prep in analysis of non-living samples, e.g. the organometallic thin films we study. If that's the case, it would be helpful to word it such that it not be taken to apply to all sample prep for TEM and SEM.
Exactly, it is a procedure that is only used for non-conductive materials.
Why do electrons lose energy when they come to electrin dense regions?
Why do we use dead samples in an electron microscope?
Why don't we use live samples?
The high-energy electrons destroy any sample.
actually living specimens can be viewed under low voltage low vacuum SEM conditions
similiar with cathode ray tube on old television
Professor Dave, do you intend to make a video or a series about Global Warming/Climate Change? Sorry for my english, it's not my native language
You didn't make any mistakes. Good job bro.
A whole series on environmental science is in the works!
@@ProfessorDaveExplains Yay, my major!
Im looking for some help. I am doing a study on the use of gel as a cleaning agent for archaeological metal objects. (about 2000 years old bronze fragments). I am however not able to detect the possible contamination of the metal sample with residue of the gel after the cleaning with certainty. Does anyone have a good way to analyze these fragments to detect the possible presence of the organic gel on the metal? I was thinking SEM/EDS could be used for this analysis. Any suggestions are appreciated. I have this far done FTIR and TGA but both of these give unclear answers possibly due to the low content of gel on the sample(or there is no presence of gel, but I can not conclude with this without having data confirming it)
EDX/TEM is probably what you want; you might look into the preparation methods used by the semiconductor industry as they often deal with thin films over metal.
@@lonnie6954 Thanks, I ended up using the Sem/EDS and EDX/TEM, it was still not possible to guarantee that there was no organic matter left on the fragments due to the gel however. As there was already some organic materials I couldn't just look for this either making it a lot more complicated to which I had to identify the structure of the gel in the organic phase etc. This I did not have time for so just delivered the study with the effect measurements and unclear about the amount of residue but I could at-least say it was not enough to really matter haha.
thank you Science Cr1TiKaL
No. Liquid cell TEM is capable for in-situ liquid samples observations.
I am here for the intro song 😄😄
SEM has worse resolution??
I have used a SEM and once found a piece of dust on my sample in the shape of the poop emoji.
So you don't get any color from these microscopes?
Colours don't exist for things smaller than a wavelength of light; you do get coloured EM images, but hey are false colours used to indicate a particular characteristic of the sample.
@@cambridgemart2075 That makes sense, thanks for the answer!
This makes me wonder, if small particles don't have color because they can't reflect light, what determines the color that's reflected from bigger things (which are made out of the smaller, uncolored particles)?
?Could you translate this video into Arabic please
.This video is very useful for students but it will be more useful if you translate it into other languages
.Please translate it into Arabic if you can
.Finally, thank you for this good explaination
I have no idea
Can you put an Arabic subtitle for the video?
can you make a 30 second video with subway surfers on the left or use a heavy accent because ive already dozed asleep 5 seconds in
Why hooman looking for really small chicks
اذا كنت عربي اضغط لايك😂❤
Everything here is in Wikipedia
Yes, it is possible to get knowledge from different places.
Am I the only one who thinks he speaks a little too fast?😂
bro that intro makes me sick. Good video though
not a very good video .. just answers half of the physical questions about the how/why the beam does its stuff, and wrong wordings too -- there are no metal "ion" but metal "atoms"! ... ionification is what happens if u use an uncoated specimen, which is what one does not want cuz then in the image u see either just a big white or black blob and nothing else. u coat it so that it becomes conductive and no ions happen
Sorry to say but why is the intro so babyish
What can he say hes a silly guy