Demonstrations and Outreach Activities

This page lists a number of experiments and demonstrations we use during outreach and similar events. Some are based on those we used in undergraduate courses, but most are geared towards a more general audience.

Basic Mechanical Properties

This is an abbreviated version of the tensile tests we do in the undergraduate courses and is used in various out-reach and open-house type events.

A sample readied for testing, with an attached extensometer that is used to measure the strain.
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Laser Diffraction

This is a nice demonstration of the phenomenon on diffraction. Students use a laser pointer and a TEM specimen grid to project a diffraction pattern on a white board or sheet of paper. The pattern is recorded using markers, then it is measured to determine the mesh size and orientation.

  • Procedure - Test procedure, with an explanation of diffraction.

Left - optical image and Fourier transform
Right - laser image and diffraction pattern
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The Black Box

This is a classic experiment that demonstrates the nature of scientific experiments, including forming a hypothesis, testing it, revising the hypothesis, and finally coming to a point where it seems this line of testing has reached its limits. While one may feel very confident on what they think is in the box, that call is still provisional. And, when a colleague conducts his/her tests on the same box, a different finding may result. Let the fun began.

Oh, and no, the students do not get to open the boxes to look inside.

  • Procedure - test procedure and suggestions on how to write the report.

Black boxes. What's inside of them?
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The Hot-wire Demonstration

It's simple. Stretch a wire between two posts, apply electrical power to those posts, and observe. The key word here, observe. How many things do you see the wire doing? Can you explain them all? Let's do it again. Did you see something else? What about the brief expansion of an iron wire when it cools? Or, what about the odd vibration nichrome wire. (You may have seen this happen in your toaster but never paid much attention to it.)

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What's in a Hard Drive?

Such high precision, such extraordinary performance, and yet cheaper than a pair of shoes. So what is inside one of these things? And how was it assembled? What materials are used?

You may think of your hard drive as being that fragile thing that holds your life's work on its spinning disks, disks that are spinning at 7200 RPM, disks that could shred your life's work in a second, without warning, much less an apology. Surely these things need to be treated with the utmost respect. Nah. Let's tear one apart.

  • Procedure - procedure and a simple worksheet

A peak at a few of the parts inside a hard disk drive.
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Analyzing Data

Opinions vary. Even when you are looking at the same data. Why is that? In this exercise we analyze the data plotted in a chart to see what each person finds and to see what each person thinks about what they find.

A plot of grains size versus annealing time. What are these results telling us?
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Project Budgets

Next week's experiment may involve breaking 40 tensile samples, or analyzing nano-powders using x-ray diffraction, or interpreting the microstructure of a piece of brass from a valve that failed. How much will that experiment cost? Or better, if this was real life, and you were being paid a real salary, how much would you have to charge someone to do this experiment or analysis?

So, figure out how much you cost on an hourly basis, after subtracting out vacations and time at work doing things you can bill for, like sitting in a meeting, and take it from there. How much will that experiment cost your customer? Or another way of looking at this, how much is what you will be learning in class next week worth on the open market?

  • Procedure - procedure and samples from a budgets spreadsheet that also lists fixed costs.

Spreadsheets are used in this exercise.
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Scavenger Hunt

This is a fun exercise where students are sent out with small cameras and a list of materials to find, photograph, and compile in a table. We use this demonstration in out-reach events and occasionally in a freshman course. By the way, it is based on a great idea by Tim Orling and Katherine Chen at San Luis Obispo. Credit where credit is due.

  • Worksheet - the list of materials to find along with clues and a place to attach the photos
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Designing Composite Materials

This is a make-and-break experiment where the students choose from a wide selection of reinforcing materials, blend it up into their plaster matrix, and when everything has set and hardened, we test it in 3-point bending. In the end it is not so much about which is the strongest, but rather what we learned about how each type of reinforcing material improved the properties of the plaster.

  • Procedure - procedure for making and testing the composites, along with worksheets for tracking the test results and the cost of materials.

The unreinforced plaster sample after fracturing during 3-point bend testing.
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Standardized Testing Methods

Some measurement tasks seem so complicated, and others, well, let's just say that different people will get different numbers and will swear by those numbers. Let's explore a standardized method for measuring grain size. This method is easier than it looks and everyone will get the same result, within the expected statistical deviation, that is.

  • Procedure - the measurement procedure along with schematics of structures to measure the grain size from.

Let's measure the grain size represented in this figure.
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