Introduction to the Scanning Electron Microscope (SEM)

Nanotechnology: A Maker's Course
Introduction to the Scanning Electron Microscope (SEM)
Link to the full Coursera course: www.coursera.org/learn/nanote...
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The Shared Materials Instrumentation Facility (SMIF) is the Pratt School of Engineering’s core facility that enables materials, devices, and integrated systems research at Duke University in a variety of fields that include nanotechnology, biomaterials and biomedical engineering, information sciences, optoelectronics, sensor technology, and renewable energy. SMIF is housed in the Fitzpatrick Center for Interdisciplinary Engineering, Medicine and Applied Sciences (FCIEMAS). The facility consists of 7,000 square feet of clean room fabrication space, and nearly 3,000 square feet of specialized laboratory space for characterization and imaging equipment. SMIF is part of the Research Triangle Nanotechnology Network (RTNN) in partnership with similar facilities at North Carolina State University and the University of North Carolina at Chapel Hill. The RTNN is one of 16 organizations nationwide that comprise the National Science Foundation sponsored National Nanotechnology Coordinated Infrastructure (NNCI) program.
SMIF is open to all trained students, staff, faculty, and researchers and is used for both research and educational purposes. SMIF has nearly 700 users, of which 2/3 come from Duke University and 1/3 come from external academic institutions or industry. SMIF staff trains students and researchers to use the lab equipment and instruments themselves, and provides guidance and support in developing processes and methodologies that utilize these capabilities. Alternatively, SMIF staff can run samples for researchers as a service. SMIF also coordinates various educational and outreach activities.

[@SamirPatnaik]

Thank you so much for this. There is no way, at this point in my life, to be anywhere near an electron microscope. This brings immense joy and hope.

[@stephaniegarcia6383]

I really liked the way that you were descriptive about how to detect secondary electrons through an electron microscope.

[@susanmatamoros3153]

I enjoyed learning about the secondary electrons, also I didn't know you could detect them by using an electron microscope!

[@sollinw]

crystal clear,very good! I hate my bad written books

[@debomondal]

Thank you very much. Everything is explained very easy way.

[@bryanhernandez3253]

Wow!! The high mode really shows the square salt molecules we see in 3-D online generated images. Super clear image I’m impressed. Excepted blurrier images! I like the explanation of details. Easy to follow!

[@avachavoshi8655]

Really cool! Thank you! :)

[@ibrakhimzhumabayev9759]

Thank you 🙏🏼

[@DeepakKumar-xr3oh]

Awesome 👍... Thanks !

[@mariamhasany5740]

please make a video on STM too!

[@omarjdominguez9752]

It was an amazing explanation. Respected professor, how should be the sample preparation process if my sample needs to be maintained in an Ar-filled atmosphere?

[@XEZGOLDZ]

found learning about secondary electron imaging really interesting!

[@thecrazyman8211]

I have one question We can use SEM for a crystalline material present in loose powder form?

[@MuhammadAliSharBaloch]

Very nice 👍 explained

[@asayilembughi8666]

Well explained

[@wilsonibeaho4788]

so helpfull.. Thank you so much

[@17rahi]

Thanks alot...

[@senaitaklog3764]

an excellent explanation I got much from your video keep it up on GC-MS if you can do it.

[@minhainguyen7154]

What parameters are important to evaluate the performance of an SEM microscope?

[@English_Lessons_Pre-Int_Interm]

this is the material which even a humanitarian mind can understand.

[@dahcari6548]

Hi Duke University - SMIF, I have question about SEM, 1/ Could SEM see nano materials, clearly or blur ? (I mean it's a normal SEM, not FE-SEM or high resolution SEM). 2/ If my material reach nano scale, could I use SEM to prove this material reach nano size? 3/ Which is the best method, cheap and convenience for characterizing (shape and size) nano materials? I hope I would receive your answer soon. Thanks Duke University - SMIF so much.

[@mmganesh6087]

intersting video . thanks for uploading. nice to see these . From India. YOur videos reach far away places and to people who have no other easy way of seeing all these. thanks again. One flatearther person told that there are no viruses. So, I started looking at how viruses are seen in sem. i wanted to know the principles. Hoping to find a virus sampling done !

[@akashanand1329]

Today i m tsking my sample for sem and i know little about it. 😂😂 thanks for simplified explanation

[@ciprianpopa1503]

0:57 electrons do not have shorter wavelengths than visible light. Accelerated electrons have shorter wavelengths.

[@mrblack9791]

just out of curiosity this thing is really simular to a standard crt monitor for old personal computers right?

[@nooryaseen9388]

If I want to assess the structure of cement concrete, I will have to dehydrate the samples, which indicates that I am going to visualize the structure without the important hydration products such as CSH (calcium silicate hydrate) and CH (calcium hydroxide). Don't you think it does not portray a good message in the field of concrete or cement. (Nevertheless, if you search about SEM of cement- or concrete-based samples, you will come across a myriad of papers incorporating SEM testing of these products.)

[@DrToyinPopoola]

Thanks for the very nice lecture. I have 2 questions. 1. If I have two SEM images taken at different resolutions and scale, how co I compare the two on a uniform scale to be able to say one particle is smaller (or bigger) than the other? 2. In the legend of an SEM micrograph taken with a desktop scanning electron-microscopes phenom-pro, there is an measurement icon that looks like an eye. Is it representing some height or what?

[@dukeuniversity-smif2466]

I am not sure about your specific SEM. In general, a given SEM will have to be calibrated at each magnification. Typically, the SEM will produce a scale bar at the bottom of the image. Note: the scale bar is only as good as the calibration and can drift with time. So, recalibration may be necessary. For the best results, it is preferred to image a known standard simultaneously to ensure the most accurate dimensional measurements.

[@nightmisterio]

why was barium titanite specifically used as a example???

[@Nur_Md._Mohiuddin_Chy._Toha]

👍👍👍

[@thecrazyman8211]

Dear I have one question for you. We cab use SEM for a crystalline material which is present in loose powder form.

[@dukeuniversity-smif2466]

Yes, you should be able to do this. We prepare this by sprinkling a fine layer of the powder onto carbon tape on an SEM stub and then sputter coat it with gold.

[@Alexandru_Narcis_Popescu]

Maybe by the year 2230 it will be possible to take such photos if with the phones

[@salaphysics6558]

I have the same issue with the explanation of the electron microscope tha I have with all explanations of electron tubes; the notion that thee is some sore of electron "beam" (consisting of electrons flowing through the device and at a fairly high percentage of the speed of light). People often ask how fast electrons flow through wires and the answer is said to be very slowly. A few hundredths of an inch per second per ampere. Although I don't think that's the actual flow of electrons but, there's a big discrepancy between hundredths of an inch per second and perhaps 150,000 miles per second as they leave a wire in a circuit and travel through a vacuum of a device and then back to plodding along again...when it's claimed (in all the electrical formulas) that the current (electron flow) is the same in all parts of a series circuit (as learned by anyone who has ever taken a class in basic electricity). How is that discrepancy explained away? I have yet to find anyone who has even tried. Yet we know, from direct observation of the circuit actions, that when a cathode is heated, that activity can be transferred to a fluorescent screen to light it up. What's the deal with that? The only answer that makes sense is that the fluorescent screen is receiving an image of the thermal activity of the cathode through some medium within the device (such as a TV CRT (Yeah, I know. Old school) or an electron microscope. A medium so mysterious and ethereal that the geniuses of science, in the 21st century still refer to it in the dictionary as a "hypothetical substance", ie" the ether. In a CRT the electrons stop at the cathode and are started up again at the anode and back through the circuit at electron-through-wires speeds. In an electron microscope the electrons stop at the cathode and pass through an accelerating electrode (called the "anode" in the schematic drawings of the electron microscope) and through other focusing and perhaps scanning electrodes but, not as electrons but, rather distortions of the ether field (which focuses the image of the cathode activity) onto the specimen. Since no electrons are striking the specimen, the image of the specimen seen also must come from the distortion of the ether field that activates the detectors (as the image of the cathode of a CRT activates the phosphors on the screen of a picture tube). In short, by thinking of the electron microscope as working by electrons striking the specimen, the engineers have fallen into the same trap that they learned (by rote and memorization) in electricity and electronics classes. Does getting the concept completely bass-ackwards prevent them from building practical devices? Obviously not but, it doesn't speak well of them when they don't care enough to try to actually undersand their chosen field of study and work. salaphyaics.com 1222922

[@NoneOfyourBusiness468]

But we didn't get a look at the coated salt crystal, only the none coated.

[@corvusblack6182]

I need to see some proof.

[@saiprakash741]

i love you are really beautiful

[@PriyabrataHalder]

Wear proper size gloves.