How Did I Live Without A Microscope?

June 26, 2021 by Elliot Williams 48 Comments

Get yourself a decent stereo inspection microscope, preferably optical. Something that can magnify from maybe 4x to 40x is fine, anything outside this range is icing on the cake. Some people claim they’re fine with a minimum of 10x, but if you go there, you’re going to need a reducing lens eventually. Either way, get one, and you’ll thank me.

How do I know this? I finally caved in and bought one about two years ago now, and while it’s not something I use daily, it’s something that I use at least once a month and for which there is simply no substitute.

This is Hackaday, so a lot of you will be thinking “inspection scope = fine-pitch soldering” and you’re not wrong. With clearance of 10 cm or more, and a slab of sacrificial optical glass (“neutral density filter”) to protect the optics from tarry flux fumes, a stereo scope at 4x makes even the fiddliest solder joints possible. Good lighting, and sharp tweezers are also a must, of course. That’s what got me in the door.

But that’s the half of it, or less. When my scope was new to me — it hasn’t been “new” since the late 1980s — we spent a whole rainy Sunday afternoon microscoping whatever would fit under the lens. Grains of salt, blades of grass, all manner of bugs living and otherwise, shells, skin, textiles. Everything is cooler under the microscope.

The event that triggered this article wasn’t my son’s school project this week to photograph dandelion seeds. Nope, today my wife found a bug in the basement; to the microscope! And with a very quick and unfortunately very positive identification, we now know that we have to strain all of our flour for bread beetles and pitch whichever bags they came in with. Hooray!

The inspection scope was intended for the soldering bench, but has found general use as an irreplaceable household tool. While I admittedly also intended to use it to lure my son into science, the real fight over scope time has been with my wife. And that’s why you want an optical scope instead of one that’s tethered to a monitor — as a general-purpose tool, portability is paramount. No menu diving, no power source, and anyone can just grab it and go.

Convinced? Ready to pull out your wallet? Microscopes are like cars. You can spend as much as you’d like on one, the cheapest will cause you nothing but pain and suffering, and the difference between the mid-range and high-end is full of diminishing returns. Buying used, especially if you can kick the metaphorical tires, can be a great bargain, and a high-end used scope will hold its value a lot better than a new budget model. Just around $200 is a sweet spot new and $300-$400 will get you the top of the line from yesteryear if you shop around. That’s not cheap, but if you’re the microscope type, it’s easily worth it. Trust me.

Microscopy Hack Chat With Zachary Tong

June 21, 2021 by Dan Maloney No comments

Join us on Wednesday, June 23 at noon Pacific for the Microscopy Hack Chat with Zachary Tong!

There was a time when electronics was very much a hobby that existed in the macroscopic world. Vacuum tubes, wire-wound resistors, and big capacitors were all mounted on terminal strips and mounted in a heavy chassis or enclosure, and interfacing with everything from components to tools was more an exercise in gross motor skills than fine. Even as we started to shrink components down to silicon chips, the packages we put them in were still large enough to handle and see easily. It’s only comparatively recently that everything has started to push the ludicrous end of the scale, with components and processes suitable only for microscopic manipulation, but that’s pretty much where we are now, and things are only likely to get smaller as time goes on.

The microscopic world is a fascinating one, and the tools and techniques to explore it are often complex. That doesn’t mean microscopy is out of the wheelhouse of the average hacker, though. Zachary Tong, proprietor of the delightfully eclectic Breaking Taps channel on YouTube, has been working in the microscopic realm a lot lately. We’ve featured his laser scanning confocal microscope recently, as well as his latest foray into atomic force microscopy. In the past he has also made DIY acrylic lenses, and he has even tried his hand at micromachining glass with lasers.

Zach is pretty comfortable working in and around the microscopic realm, and he’ll stop by the Hack Chat to share what he’s been up to down there. We’ll talk about all the cool stuff going on in Zach’s lab, and see what else he has in store for us.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, June 23 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.
Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Macro Model Makes Atomic Force Microscopy Easier To Understand

June 12, 2021 by Dan Maloney 6 Comments

For anyone that’s fiddled around with a magnifying glass, it’s pretty easy to understand how optical microscopes work. And as microscopes are just an elaboration on a simple hand lens, so too are electron microscopes an elaboration on the optical kind, with electrons and magnets standing in for light and lenses. But atomic force microscopes? Now those take a little effort to wrap your brain around.

Luckily for us, [Zachary Tong] over at the Breaking Taps YouTube channel recently got his hands on a remarkably compact atomic force microscope, which led to this video about how AFM works. Before diving into the commercial unit — but not before sharing some eye-candy shots of what it can do — [Zach] helpfully goes through AFM basics with what amounts to a macro version of the instrument.

His macro-AFM uses an old 3D-printer as an X-Y-Z gantry, with a probe head added to the printer’s extruder. The probe is simply a sharp stylus on the end of a springy armature, which is excited into up-and-down oscillation by a voice coil and a magnet. The probe rasters over a sample — he looked at his 3D-printed lattices — while bouncing up and down over the surface features. A current induced in the voice coil by the armature produces a signal that’s proportional to how far the probe traveled to reach the surface, allowing him to map the sample’s features.

The actual AFM does basically the same thing, albeit at a much finer scale. The probe is a MEMS device attached to — and dwarfed by — a piece of PCB. [Zach] used the device to image a range of samples, all of which revealed fascinating details about the nanoscale realm. The scans are beautiful, to be sure, but we really appreciated the clear and accessible explanation of AFM.

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Optical Microscope Resolves Down To 40 Nanometers

June 2, 2021 by Al Williams 12 Comments

Optical microscopes depend on light, of course, but they are also limited by that same light. Typically, anything under 200 nanometers just blurs together because of the wavelength of the light being used to observe it. However, engineers at the University of California San Diego have published their results using a hyperbolic metamaterial composed of silver and silica to drive optical microscopy down to below 40 nanometers. You can find the original paper online, also.

The technique also requires image processing. Light passing through the metamaterial breaks into speckles that produce low-resolution images that can combine to form high-resolution images. This so-called structured illumination technique isn’t exactly new, but previous techniques allowed about 100-nanometer resolution, much less than what the researchers were able to find using this material.

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Repurpose A Monitor Arm As Microscope Mount

May 16, 2021 by Chris Lott 12 Comments

Being a bit shocked at the prices of articulating arm microscope mounts, not to mention the shipping fees to the UK, [CapTec] realized they looked substantially similar to your typical computer monitor arm mount. Thinking he could adapt a monitor arm for much less money, he fired up FreeCAD and started designing.

[CapTec] is using this to support his Amscope / Eakins camera-equipped trinocular microscope, but notes that the same mechanical bracket / focus rack interface is found on binocular ‘scopes as well. He observes that the mount is no more stable than your desk or lab bench, so keep that in mind.

Ultimately the monitor arm set him back less than $40, and all told he reckons the whole thing was under $55. Based on prices he’s been researching online, this represents a savings of well over $200. In his calculations, the shipping fee comprised quite a hefty percentage of the total cost. We wonder if they are artificially high due to coronavirus — if so, the make / buy price comparison might yield different results in the future.

This type of project is a perfect use-case for a home 3D printer — making your own parts when the normal supply channels are unavailable or overpriced. Are articulating arms that are purpose-built for microscopes significantly different than those designed for big computer monitors? If you know, please comment down below.

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3D-Printed Laser Scanning Confocal Microscope Measures Microns

April 26, 2021 by Dan Maloney 15 Comments

When one thinks about microscopy, it seems to be mostly qualitative. Looking at a slide teeming with bacteria or protozoans is less about making measurements and more about recognizing features and describing their appearance. Not all microscopes are created equal, though, with some being far more optimized for making fine measurements of the microscopic realm.

This 3D-printed confocal laser scanning microscope is a good example of an instrument for measuring really small stuff. As [Zachary Tong] points out, confocal scanning microscopy uses a clever optical setup to collect light from a single, well-defined point within a sample; rather than getting an image of all the points within a two-dimensional focal plane, the scanning function moves the focal point around through the sample in three dimensions, capturing spatial data to go along with the optical information.

The stage of [Zach]’s microscope is based on OpenFlexure’s Delta Stage, an open-source, 3D-printed delta-bot motion control platform that’s capable of positioning samples with sub-micron precision. Above the stage are the deceptively simple optics, with a laser diode light source, an objective lens, and a photodiode detector behind a pinhole. The detector feeds a homebrew trans-impedance amplifier that captures data at millions of points as the sample is moved through a small three-dimensional space. All that data gets crunched to find the Z-axis position corresponding to the maximum intensity at each point.

It takes a while to gather all this data — up to several days for even a small sample — but it works pretty well. [Zach] already has some ideas for reducing noise and speeding up the scan time; perhaps a stage based on DVD parts like this one would be faster than the delta stage. We look forward to seeing his improvements.

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Modified 3D Printer Makes A Great Microscope, Too

February 26, 2021 by Lewin Day 15 Comments

A false-color polarimetric image of sugar crystals floating in water.

Look past the melty plastic bits, and your average 3D printer is just a handy 3-axis Cartesian motion platform. This makes them useful for all kinds of things, and as [E/S Pronk] shows us, they can easily be modified into an automated polarimetric microscope!

The microscope build actually took two forms. One, a regular digital microscope any of us may be familiar with, using a C-mount microscope lens fitted to a Raspberry Pi HQ camera. The other, a polarimetric microscope, using an Allied Vision Mako G-508B POL polarimetric camera instead, with the same microscope lens. The polarimetric camera takes stunning false-color images, where the color values correspond to the polarization of the light bouncing off an object. It’s incredibly specialized hardware with a matching price tag, but [E/S Pronk] hopes to build a cheaper DIY version down the line, too.

3D printers make excellent microscopes, as they’re designed to make small precise movements and are easily controlled via G-Code. We’ve seen them used for other delicate purposes too – such as this one modified to become a soldering robot. Video after the break.

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