Demo samples for school projects
Margo Gill-Linscott
On Jun 21, 2010, at 9:12 AM, kaml...@yahoo.com
wrote:
Hi listers,
In a turn of events that will make many of you smile knowingly, I've
been asked to give a half day, hands-on "workshop" on "EM"
as a
professional development activity for some local high school science
teachers. It's a great idea, but, as you all well know, there is
just no such thing as throwing something on the SEM or TEM for a
"quick pic"! Thankfully, we have an SEM
with LV capabilities so that
we can look at unfixed samples!
Some of these teachers are physics teachers and so probably not so
excited about looking at the biological samples with which I am well-
acquainted and bringing the micrographs back to their students. Do
any of the materials scientists out there have a suggestion for an
easy (and easily available) materials sample to look at with these
teachers?
Thanks in advance for any advice that you can offer,
Kristen Lennon
Frostburg State University
Dept of Biological Sciences
Frostburg, MD 21532
kale...@frostburg.edu
http://www.frostburg.edu/dept/biol/
Light bulb filament sample
For any kind of student demo, you want to have a "hook" to engage the
students. We used a "CSI" theme and used light bulb filaments
as our
samples. Our "story" was about a car accident where there was a
disagreement about whether the driver had his headlights on at the time
of the accident. The driver claimed his headlights were on and the
other person claimed that the driver turned on his lights after the
accident to make it LOOK like they were on. I showed 2 burned-out light
bulb filaments; one of which was burning when I broke the glass, the
other of which I broke the glass envelope and and
then excited the
filament.
The filament which was hot when broken had glass embedded in the
filament wire, while the other was just oxidized. The glass globules
were quite visible embedded in the tungsten wire and I could then use
EDX to identify the particles. In the ensuing discussion, I had the
students deduce the actual scenario.
Note: be careful on breaking the bulbs. Glass can go flying
everywhere. I put mine in a paper bag and then used a vise to slowly
crack the glass envelope (so I didn't damage the filament).
Cheers,
Henk
At 6/21/2010 12:03 PM, kaml...@yahoo.com
wrote:
CD technology samples
-----Original Message-----
X-from: jeh...@mta.ca
[mailto:jeh...@mta.ca]
Sent: Tuesday, June 22, 2010 6:03 AM
To: swa...@southbaytech.com
Subject: [Microscopy] Demo sample
Bugs are always a big hit, but one set of samples I usually get a lot of
interest in from kids of all ages is record grooves vs. pits on a CD.
Usually the older generation gets involved describing to their
grandchildren what exactly a record was, and a lively discussion of
analog versus digital music develops. Seeing one at relatively low
magnification vs the other at high mag really drives home the advance of
technology. Having a computer chip in the scope at the same time usually
goes over well. The hassle of dissolving the CD and burning off the chip
packaging is well worth it, and once prepared, they can last for years.
Oh, there's also this: take the back off of an old (but working)
mechanical wristwatch. Watching the spring and gears move at TV rates is
oddly hypnotic. Dropping into slow scan mode also works into the
explanation of how the image is formed.
Over the years, I seem to get the best reaction from microscopical
novices if they look at things they have some sort of connection with at
a scale they are used to in normal life.
Hope this helps,
Jim
Jim,
The preparation of a CD is quite simple. You don't have to burn off the
plastic at all. Take a commercially prepared CD, not a recordable one,
and
cut a square in the top label side of the CD with a razor blade. Then
take
Scotch® tape and firmly press it onto the area that you scored with the
razor blade. When you remove the tape, the recording will come up and you
can put it in the microscope.
-Scott
Scott D. Walck, Ph.D.
Technical Director
South Bay Technology, Inc.
1120 Via Callejon
San Clemente, CA 92673
US Toll Free: 1-800-728-2233
Tel: (949) 492-2600
Fax: (949) 492-1499
www.southbaytech.com
swa...@southbaytech.com
James M. Ehrman
Digital Microscopy Facility
Mount Allison University
63B York St.
Sackville, NB E4L
1G7
CANADA
phone: 506-364-2519
fax: 506-364-2505
email: jeh...@mta.ca
www: http://www.mta.ca/dmf
Metal wrapper from a chocolate egg
Email: in...@savion.huji.ac.il
Name: Inna Popov
Organization: The Hebrew University of Jerusalem
Title-Subject: [Filtered] SEM Materials - Demo
Message: Hi,
Once in the past I used to demonstrate SEM to 7 years old children.
Observation of a coin had attracted their attention. But, to be
honest they were too young.
Later I took colledge students to SEM&EDS lesson
and used two metal
soliers from chocolate egg
( see the link:
http://www.soldatiki.ru/2008/soldatiki.php?page=10&lang=en).
Such
objects attracts a lot of interest, because they have a story behind
(ancient art of metallurgy, history of Roman Empire -
depends on what
you show). They story is a key point which will
remain in the memory
of pupils. And you simultaneously demonstrate 1)typical
defects of
casting; 2) chemical composition; 3)brittle fracture of casting (no
problem to break some tiny part of a soldier) and whatever you wish
to add.
Alternatively, you may take a plastic toy from a KinderJoy
egg, use
LV mode, show magnified SE image of the object, explain why they do
not see colors, how to reconstruct a preparation way, i.e. story.
Saline on steel-rust
The last attractive thing I may imagine is simply corrosion deposite.
A day before the lesson put a drop of saline on a piece of steel
(magnesium alloy is better). At the lesson you will demonstrate
beautiful aestetic oxide-hydroxide flower-like flakes
and give a
story.
Good luck,
Inna
Bugs
Hmm, fun. I run a couple of "Grandparents
University" sessions here in
the summer
(tomorrow) -- grandparents and their grandkids.
This would be fun, but the cool purple glow of
the sputter coater always gets the kids excited
for the rest of the session. Which is "bring a
bug, and we'll look at it in the SEM". A big
favorite.
I've thought of sawn/cut metal vs brittle
fracture in LN2, but really, looking at bugs they
caught gets the kids the most excited, and that's
where all our obsessions started, yes?
Fly
Phil
When I was at PPG's Glass
Technology Center,
we had an open house for family
members. We did a demo on the SEM that was kind of neat. We set
them up
for a punch line at the end of the demo. Here's what we did:
We took a dead fly and heavily coated it with gold. It was a really thick
layer of gold. This was done prior to the demonstration. Our real
sample
was a cross section of enamel on glass that we wanted to show the layers and
components and measure the different phases with the XEDS to show how we
measure composition.
To introduce them to the SEM, we showed them the fly. Scanned it all over
and explained how the image was formed. We did not tell them it was
coated.
Of course, they thought that it was neat.
Then we moved to the cross section sample and showed how we measured the
composition of the different phases with the X-ray system. Oh-hum,
kind of
boring.
Then we asked them "what was the composition of the fly?" Some
would say
C,H,O or whatever their guesses were. We then
said, "Well, let's find out
for sure." And, of course, the only thing that came up was gold in
the
spectrum. We then asked, "Why is it gold?" and then let them
guess. At the
end, if they didn't know, we asked them if we could interest them in stock
certificates in the "PPG Lost Gold Bug Mine" which were certificates
that we
made up with a big yellow faux colored SEM image of the fly, the X-ray
spectrum in the background, and the signed signatures of our group members
as officers in the "PPG Lost Gold Bug Mine Corporation"
. I think that it
went over fairly well and the kids were carrying around their stock
certificates all day.
-Scott
Scott D. Walck, Ph.D.
Technical Director
South Bay Technology, Inc.
1120 Via Callejon
San Clemente,
CA 92673
US Toll Free: 1-800-728-2233
Tel: (949) 492-2600
Fax: (949) 492-1499
www.southbaytech.com
swa...@southbaytech.com
Hair
Hi
When demonstrating to 6th formers I've asked for
volunteers to provide
hair samples, stuck them on a stub & imaged them (in esem
uncoated) Try
& get a variety of hair types to see differences.
Good luck with the demo
Nikki
This message has been checked for viruses but the contents of an attachment
may still contain software viruses which could damage your computer system:
you are advised to perform your own checks. Email communications with the
University of Nottingham
may be monitored as permitted by UK
legislation.
==============================Original Headers==============================
1, 35 -- From Nicola...@nottingham.ac.uk
Tue Jun 22 04:21:58 2010
I encountered the same situation on a number of occasions over the
years I was teaching electron microscopy. I am reluctant to admit
it, but the SEM sample that got the greatest attention
from high
school students was an ant, and next best (and more difficult to
prepare) was a mosquito. I hate to admit it, but beautifully etched
specimens of pearlitic steel mostly left them cold.
--
Wilbur C. Bigelow, Professor
Emeritus
Materials Sci.
& Engr., Univ. of Michigan
Ann Arbor, Michigan 48109-2136
e-mail: big...@umich.edu;
Fx:734-763-4788; Ph:734-975-0858
Address mail to: 2911 Whittier Court
Ann Arbor, MI
48104-6731
Paper
Kristen,
You can use paper. Place on the stub two pieces of paper: writing
paper and filter paper. You can see paper fibers and filler particles in
writing paper (no particles in filter paper). You can check distribution
of filler with BSE and composition with EDS (usually some salts of Ca).
Vladimir
Vladimir M. Dusevich, Ph.D.
Electron Microscope Lab Manager
371 School of Dentistry
650 E. 25th Street
Kansas City, MO 64108-2784
River bottom mud
Dear Kristen,
I am not a materials person, but I did have a project looking at
sediment from river bottoms. The samples are very easy to prepare--
just suspend the mud in a fairly dilute suspension, let the larger
particles settle, then put a drop (a few ul will do)
onto a carbon/
formvar coated grid and let dry. If my
experience was typical, you
will see diatom skeletons, mineral fragments, crystalline and not, and
other items in a TEM image. EDS (if available) will also show some
surprises for some of the particles. I saw U and Au in addition to
the usual suspects, Na, K, Si, Al,
Ti, Ca, etc. Good luck.
Yours,
Bill
PS. I am no longer working for FEI.
Stainless Steel, microvoid coalescence and cleavage, brittle failure samples
Dr.
Lennon,
According to your web site, your University has a Materials Engineering
department. They probably have a tensile tester and may have a Charpy Impact tester. In any case, they have the
capacity to break steel samples.
So ask for two pieces of the same steel, one fractured at room temperature and
one at depressed (LN) temperature. People realize that things can get
brittle at low temperature. The vivid difference between microvoid coalescence (overload) and cleavage (brittle) as
seen in the SEM, at relatively low magnification, is something a Physics
teacher or student will find immediately captivating.
And if they ask you why the steel behaves like that, just look smug and inform
them that they need to attend classes to find out.
Regards,
Andrew Werner
Chief Metallurgist, Perforating
Schlumberger Reservoir Completions
14910 Airline Road
Rosharon, TX 77583
Light bulb filament; ball point pen tip samples
Microscope light bulb filaments are always of interested, especially
burnt
out ones. Be careful cutting the glass envelope with a scriber and
breaking it. Ball point pen tips are interesting (make sure you clean the
ink out) as are tips of hypodermic needles, especial one with compound
bevels, metal savings (file a penny and nickel to met
a mixed metal to demo
EDS if you have it).
What you need next is a little fictional story I which the investigator
solves some problem/crime/mystery with the sample you have in the scope.
I
have always found the trick, it is a trick is to slant
the story to involve
the audience.
Have fun...
Frank
Eggshell & butterfly wingscale samples
Hi Kristen,
2 low prep samples that show a nice fusion of biology and
physics/engineering principles are a butterfly wingscale
and the
structure of a chicken eggshell. I have images on my website. Neither
requires critical point drying; just mount and sputter. The eggshell is
the surface exposed when the inner tough membrane layer is peeled off
(bet someone knows the official name....), but both sides are
interesting - outer surface shows the various fine CaCO3 beads that
scatter light so nicely...
The xylem image is a confocal one, but could be
prepped for SEM. It is
made by finding the nice weed common here - Plantago
_ and nicking the
petiole with a razor or fingernail and pulling apart - stripping out the
vascular bundles (like celery strings - that would do also...); these
wall thickenings support the xylem from collapsing due to atmospheric
pressure when there is greatly lowered pressure from transpiration in
the leaves (how much pressure does it take to get water to the top of a
redwood?)
http://www.bio.umass.edu/microscopy/gallery.htm
Hope this helps,
Dale
Metal Corrosion Samples
Kristen,
Several years ago a group from Dupont in Delaware
gave a presentation at the Philadelphia Society for Microscopy, mostly
biological focused. They showed SEM images of failure analysis that was
of interest to all in that they could not show failure analysis of their work
projects. Some that I remember were a screw that had to top twisted off
and a broken flusher handle from a toilet. These showed force and
corrosion. Perhaps you have something broken like these at home.
Pat
Patricia Stranen Connelly
Research Assistant
NHLBI Electron Microscopy Core
National Institutes of Health
14 Service Road West
Bldg. 14E - Rm. 111B MSC 5570
Bethesda, MD 20892-5570
Phone 301-496-3491
conne...@mail.nih.gov <mailto:conne...@mail.nih.gov>
Opinions and experiences related are those of Pat Connelly and do not represent
the NIH. This message is not confidential and can be freely shared and
reproduced