Building an Atomic Force Microscope on the Cheap!

LEGO2NANO, are building an open hardware AFM (Atomic Force Microscope).

AFMs are a kind of probe microscope. Unlike an optical microscope, a probe is used to “feel” the topology of a surface. An atomic force microscope uses a flexible cantilever with a nanometer scale tip on the end. As the tip scans across the surface it will be deflected by its interaction with the surface. A laser spot is usually reflected off the back of the cantilever, and captured by a photodiode array. The angle of the reflected beam, and therefore which photodiodes are excited lets you know how much the cantilever was deflected by the surface.

One of the challenges of building an AFM is developing an actuator that can move with nanoscale precision. We recently reported on [Dan Berard]s awesome capacitor actuator, and have previously reported on his STM build which uses a piezo buzzer. LEGO2NANO are experimenting with a number of different configurations, including using Piezo buzzers, but in a different configuration to [Dan]s system.

The LEGO2NANO project runs as a yearly summer school to encourage high school students to take part in the ambitious task of building an AFM for a few hundred dollars (commercial instruments cost about 100,000USD). While the project isn’t yet complete, whatever the outcome the students have clearly learned a lot, and gained an exciting insight into this cutting edge microscopy technique.

Hackaday Prize Entry: Online Bone Marrow Cytometry Aid

Simple blood tests can lead a doctor toward a diagnosis of blood cancers, like leukemia, lymphoma and myeloma, but to really see what’s going on, he or she needs to go to the source of the problem: the bone marrow. Examining maturing blood cells from the marrow with a microscope is an important step in staging the disease and developing a plan for treatment, but it’s a tedious and error-prone process that requires a doctor to classify and tally a dozen or so different cells based on their size, shape and features. Automated systems like flow cytometry and image analysis software can help, but in an austere environment, a doctor might not have access to these. Luckily, there’s now an on-line app to assist with bone marrow cytometry.

Thanks to [Eduardo Zola], a doctor can concentrate on classifying cells without looking up from the microscope, and without dictating to an assistant. Keys are assigned to the different cell morphologies, and a running total of each cell type is kept. With practice, the doctor should be able to master the keying for the various cells; we suspect the generation of physicians that grew up with the WASD keying common in PC-based gaming might have a significant advantage over the older docs when it comes to learning such an app.

[Eduardo]’s app seems like a simple way to improve on an important medical procedure, and an enabling technology where access to modern instrumentation is limited. To that end, one area for improvement might be a standalone app that can run on a laptop without internet access, or perhaps even a version that runs on a smart phone. But even as it is, it’s a great entry for the 2015 Hackaday Prize.

The 2015 Hackaday Prize is sponsored by:

Microscope Camera For Zeroing CNC Machines

After what we’re sure is several dozen screw-ups or at the very least a lot of wasted hours, [Chris] has gotten around to building a very precise microscope camera mount for zeroing out his CNC machine.

If you need to mill a few bits out of a sheet of metal or plastic, it’s important to know exactly where you’re cutting. A CNC machine can take care of the relative positioning, but if you already have half your holes drilled, you also need absolute positioning. This means placing the work piece exactly where you want to cut, or failing that, zeroing the machine to a predefined point on the piece.

[Chris] is accomplishing this with a pen-shaped USB microscope. With a 3D printed mount and a few magnets, this camera can clip right on to the machine, and with the camera interface in Mach3, it’s pretty easy to zero out the mill to within a thousandth of an inch.

There’s a video demo of the camera in action below, but there’s a lot more CNC mods on [Chris]’ website. There’s custom 3D printed vacuum nozzles, and a lot of work on a small desktop Grizzly mill.

Continue reading “Microscope Camera For Zeroing CNC Machines”

Cheap DIY Microscope Sees Individual Atoms

This is not an artist’s rendering, nor a physics simulation. This device held together with hardware-store MDF and eyebolts and connected to a breadboard, is taking pictures of actual atomic structures using actual measurements. All via an 80¢ piezo buzzer? Madness.

Gold atoms in a crystal.

This apparent wizardry is called a scanning tunneling microscope which takes advantage of quantum tunneling. The device brings a needle atomically close to the object to be measured (by hand), applying a small voltage (+-15V), and stopping when it starts to conduct. Depending on the distance between the tip and the target, the voltage varies and does so precisely enough to identify whether an atom is underneath or not, and by how much.

The “pictures” are not photographs like a camera might take from a standard optical microscope, however they are neither guesses nor averages. They are representations of real physical measurements of specific individual atoms as they exist on the infinitesimal area being probed. It “sees” by measuring small voltage changes. Another difference lies in the “scanning.” The probe examines atoms the way one would draw ASCII images – single pixels at a time until an entire atom was drawn. Note that the resolution – as shown in the pictures – is sub-atomic. Sizes of atoms are apparent as are the distances between them. In this they are closer related to the far more expensive Scanning Electron Microscope technology, but are 10-100x zoomier; resolving 0.00000000001m, or 0.00000000039″.

Scan Head – Piezo cut into quadrants

One would presume that dealing with actual atoms requires precision machining vast orders of magnitude beyond the home hobbyist but, no. Any one of us could make this at home or in our hackerspaces, for nearly free. Apparently even sharpening a tip to a single atom is, as [Dan] says “not as hard to achieve as you might think!” You take some tungsten wire and pull on it as you cut so that it shatters diagonally. There are better ways he suggests, but that method is good enough.

The ordinary piezo buzzer that is key to the measurement is chopped into quadrants with an ordinary X-Acto knife by hand. Carefully, because it is fragile, but, nothing more to it than that. There are two better and common methods but they cost hundreds of dollars, not 80 cents. It should be carefully glued since soldering heat will damage it, but, [Dan] soldered his anyway because it was easier. Continue reading “Cheap DIY Microscope Sees Individual Atoms”

DIY Video Microscope Used For Soldering SMD Parts

Fortunately (or unfortunately), [ucDude] has had the opportunity to try out a high quality video microscope while soldering some small surface mount components. He loved it, the problem was he had a hard time going back to using just his eyes. He wanted a video microscope but the cost for a professional one could not be justified. The solution? Build one!

[ucDude] called on one of his photographer friends to help. After discussing the project they decided to use a webcam and a lens from an SLR camera. Testing with the webcam resulted in an image that could not be zoomed-in enough, plus having to connect it to an external computer proved to be a bulky solution. They next tried a Raspberry Pi, camera module and zoom monocular. It worked great! The entire assembly was then mounted to a camera boom stand making it easy for the camera to be positioned over the work area and out of the way of hands and soldering irons. The Raspberry Pi’s HDMI output is plugged straight into an HD monitor. The result is exactly what [ucDude] was looking for. Now he can quickly and confidently solder his surface mount circuit boards.


Finding And Repairing Microscopes From The Trash

scope We’re not quite sure where [Andy] hangs out, but he recently found a pile of broken microscopes in a dumpster. They’re old and obsolete microscopes made for biological specimens and not inspecting surface mount devices and electronic components, but the quality of the optics is outstanding and hey, free microscope.

There was a problem with these old scopes – the bulb used to illuminate specimens was made out of pure unobtainium, meaning [Andy] would have to rig up his own fix. The easiest way to do that? Some LEDs made for car headlights, of course.

The maker of these scopes did produce a few for export to be used in rural areas all across the globe. These models had a 12 Volt input to allow the use of a car battery to light the bulb. A LED headlight also runs off 12 Volts, so it was easy for [Andy] to choose a light source for this repair.

A little bit of dremeling later, and [Andy] had the new bulb in place. An off the shelf PWM controller can vary the brightness of the LED, controlled with the original Bakelite knob. The completed scope can easily inspect human hairs, the dust mites, blood cells, and just about anything down to the limits of optical microscopy. Future plans for this microscope might include another project on, a stage automator that will allow the imaging of huge fields at very high magnification – not bad for something pulled out of the trash.

A DIY Atomic Force Microscope


For looking at really small stuff, an optical microscope will only go so far. Looking at things at the nanometer level, though, usually requires some sort of electron microscope, with all the hassle of vacuum chambers and high voltages. There is another way to investigate the domain of the very small: an atomic force microscope. Unlike their electron spewing brothers, they don’t require high voltages or hard vacuums. They can also be built for about $1000, as [whoand] over on the Instructables shows us.

Instead of shooting light or electrons at an object and picking up the reflections, an atomic force microscope drags a very, very tiny stylus across an object. This stylus is attached to a probe that will reflect laser light off of it into a photosensor, eventually rendering an image on a display. [whoand] is using a laser diode and pickup unit from a DVD-ROM drive for the optical pickup unit, a frame made from soldered together PCBs, and a few piezos to vibrate the probe.

The probes themselves are incredible pieces of engineering with a tip size of a few nanometers. They’re consumable, and expensive, ranging from $20 to $500 per probe. Still, with these probes, [whoand] can look at the pits in a CD or DVD, measure the surface of an eraser, or check out the particulate matter floating around in the atmosphere in Beijing.

Thanks [Rob] for the tip.