Introduction

     Hello, and welcome to Virtual Microscope (VM), a component of NASA Learning Technologies Virtual Lab project. The steps below will walk you through a few of the major Virtual Microscope features.

     Double click on the file VirtualLab.jar to start Virtual Microscope. The initial image you see is that of a beetle being viewed with a scanning electron microscope (SEM). This image is actually composed of many smaller images, displayed as a collection of tiles to appear as one image. The images were created by automated software that modifies the SEM's stage, magnification and focus. In the set of images for the beetle, including all its magnifications and focal distances, there are 7,882 image tiles. Each one is 256x256 pixels square. The full set requires 85 megabytes of file storage.

     At the upper right of the VM window is the magnification control panel. Click on the "221x" entry in the menu to display the beetle at 221-times magnification. You can also select any of the other listed magnifications; VM will display the beetle at the one you select.

     Move the cursor a little to one side of the center of the VM window and press the left mouse button. This controls the SEM's stage, which moves the specimen under the SEM electron beam. The farther the cursor moves from the center of the window, the faster the stage moves. The stage may seem to you to move the "wrong" direction, away from the side at which you place the cursor. But that's the way an SEM really works: the operator positions the cursor towards the location she wants to see.

     At the bottom right of the VM window is another menu. This one selects the focal plane. Specimens such as the beetle that have depth require focal-plane adjustment in order to view clearly the portions of the specimen in relief. As you select each available focal plane, notice that some portions of the image become sharper, and some portions become fuzzy. This simulates the focus adjustment on the real SEM.

     Now measure something on the beetle using the measurement tool in the upper left corner of the VM window. Click on the digital readout of the tool and slide it over to your selected measurement location while you hold down the left mouse button down. Once you place it near the feature to measure, select either end of the measurement tool to precisely position that endpoint; do the same with the other end. The digital readout in the center of the tool indicates the length between the endpoints, and the units of length.

     To measure another area, either click on the center or endpoints of the measurement tool you just used, or again drag a tool from the permanently positioned one in the upper left corner of the window. You can have any number of measurement tools on the screen at once. To delete any of them, right click over the tool and select "Delete Measure." The permanently positioned tool can not be deleted, of course.

     Now view another specimen: Select "Integrated Circuit" from the VM's Specimen menu in the menu bar. This specimen is very flat, so there is no focus control. The SEM was focused on the ICs upper surface. Notice that the focal-plane menu is now not displayed. You can manipulate and measure this specimen in the same ways you did the beetle specimen.

     Two other specimens are provided with this review version of Virtual Microscope: "Kidney Stone" and "Texas Instruments DLP Chip." Feel free to take a look at those if you like.

     The first two items on the Specimens menu are listed but are not yet available. These entries are placeholders for web-accessible specimens, which are not yet in place. When they are, selecting them from the Specimen's menu will cause VM to retrieve them from their location on the internet.

     Sometimes users wish that the magnification and focal-plane menus were at other locations on the VM window. No problem: just click on their titles with the left mouse button and slide them to a new location while holding the button down. Note that their backgrounds are transparent, so they won't hide the specimen if they overlie it.

     Controls are being added to measure areas, and to adjust the contrast and brightness of the image. The latter can sometimes help to discern features in the specimen that are apparent only at certain contrast or brightness.

     To exit VM, simply close the window by selecting its "Close" window system icon.

     Thanks for exploring Virtual Microscope! Please let us know if you encountered any problems or have suggestions for improvement.

	Virtual Lab is developed at NASA Kennedy Space Center by principal investigator Berta Alfonso. Implementation and imagery were provided by The Beckman Institute at the University of Illinois at Urbana-Champaign, co-producers Glenn Fried and Benjamin Grosser.