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How the Zoomy Handheld Digital Microscope Works

BY Joe McCormick / POSTED February 26, 2013
© Steve Gschmeissner/Science Photo Library/Corbis © Steve Gschmeissner/Science Photo Library/Corbis

I wish I had one of these things when I was a kid.

The Zoomy Handheld Digital Microscope looks like a little blue Easter egg that connects to your computer via USB port. The egg itself is the camera, and the operation is pretty simple: On one end there is a lens and a set of bulbs that provide a quad-blast of LED light on the surface of the magnification subject. On the other end is a knob for focus and capture control. From a tech/design standpoint, the microscope looks super user-friendly. It draws all the power it needs directly from your computer’s USB port, and it takes highly magnified digital pictures – even video – that transfer directly to dedicated software on the computer.

The image sensor itself is a 350,000-pixel VGA complementary metal-oxide semiconductor (CMOS), which this short HowStuffWorks article does a good job of explaining. Essentially, a CMOS image sensor is a flat array of photosensitive cells used to convert light patterns into electrical data that the camera can translate into a digital file, like a BMP or a JPEG. A CMOS is usually a lower-resolution but higher-efficiency option than your average charge-coupled device (CCD) – the latter of which is the kind of sensor you might find inside a lot of high-quality digital cameras.

While the capture resolution offered by the microscope could be higher (640×480 VGA), it’s still way cool, and my guess is that a slightly lower-res but less-energy-hungry CMOS is what allows it to draw power straight from the USB for, say, continuous video capture, rather than relying on batteries or external power hookup. I also imagine it helps keep the model as (relatively) cheap as it is.

When I got my first microscope, I remember using it basically like a kaleidoscope – I’d squash some kind of goo onto a slide and then look at it under all the different settings, but since I didn’t understand what I was looking it, it was basically just like watching a sluggish, monochrome version of the media player visualizations on my computer. As weird as it seems, though, I really think that’s enough to plant the germs of science in a fledgling brain. In fact, I’d argue that the point of a microscope for kids isn’t to make them hardcore microbiologists who understand the exact role the mitochondrion plays in the energy cycle of a eukaryotic cell. Instead, I think what a kids’ microscope does is make young people feel the weirdness of scale. There is a world much bigger than us and a world much smaller than us, and once we zoom far enough in or out, we are in unknown territory of the brain-melting variety.

From what I can tell, when I was a kid I had something almost exactly like this kit (probably from the same manufacturer, since all of the accompanying tools look familiar to me), which does go up to several hundred times magnification. With the Zoomy, the brute force level of magnification isn’t the big draw. To be specific, it’s 35x to 53x magnification (when sent to a 14” monitor). No doubt that’s plenty to create some amazing images. The kids aren’t going to be spotting the double helix, but it’s definitely enough of a challenge to normal interpretations of scale to set a kid back on her heels and make her feel the weirdness.

One interesting difference between the traditional microscope kit and the experience the Zoomy offers is the direction of the lighting – most of the microscopes I remember looking at throughout the years were “bright field” microscopes, which used transillumination, or back-lighting. The light shone upward from a lamp at the base, through the slide, directly into the lens, passing through the sample on its way to your eye. Zoomy, on the other hand, uses reflected light: LEDs shine down from the handheld probe to illuminate the surface of the sample. I guess this could have drawbacks, in that it doesn’t seem to create the kind of penetrating cross-section image we often see of, say, clusters of body cells on a bright field microscope slide. With the Zoomy, you don’t see light streaming through the guts of the sample.

On the other hand, if you look at the Zoomy images you can find online, it seems the reflected light and digital capture creates an image that is much more “textured” and recognizable as the kind of matter we deal with every day – only really, really detailed and huge. It doesn’t look like gray squiggles entering a tunnel of light on their way to gray squiggle heaven. It looks like the stuff we’re used to seeing – solid surfaces made of solid materials that can be touched. And this is actually kind of cool, in that it enforces the idea that we’re not entering a fake fantasy world when we look through a microscope. We’re actually seeing a dead spider’s chelicerae, or a dusty flower stamen, or some little chunk that got stuck in your toothbrush, except on a scale that’s more alien to us than any foreign planet. And we feel the weirdness all the more.

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