As smartphones become more ubiquitous in society, they are being used in plenty of ways not imaginable even ten or fifteen years ago. Using its sensors to gather LIDAR information, its GPS to get directions, its microphone to instantly translate languages, or even use its WiFi and cellular radios to establish a wireless hotspot are all things which would have taken specialized hardware not more than two decades ago. The latest disruption may be in microscopy, as this build demonstrates a microscope that would otherwise be hundreds of thousands of dollars.
The microscope is a specialized device known as a fluorescence microscope, which uses a light source to excite fluorescent molecules in a sample which can illuminate structures that would otherwise be invisible under a regular microscope. For this build, the light is provided by readily-available LED lighting as well as optical filters typically used in stage lighting, as well as a garden-variety smartphone. With these techniques a microscope can be produced for around $50 USD that has 10 µm resolution.
[A. Cemal Ekin] over on PetaPixel reviewed the Apexel 200X LED Microscope Lens. The relatively inexpensive accessory promises to transform your cell phone camera into a microscope. Of course, lenses that strap over your phone’s camera lens aren’t exactly a new idea, but this one looks a little more substantial than the usual piece of plastic in a spring-loaded clip. Does it work? You should read [Cemal’s] post for the details, but the answer — as you might have expected — is yes and no.
On the yes side, you can get some pretty neat photomicrographs from the adapter. On the negative side, your phone isn’t made to accommodate microscope samples. It also isn’t made to stay stable at 200X.
The wand-like device is made by Gelsight, and instead of an optical lens like a normal microscope, it sports a gel pad on the sensing end. By squashing an object into the gel, the device is able to carefully illuminate and image the impression created. By taking multiple images lit from different angles, a lot of information can be extracted.
The result is a high-resolution magnification — albeit a monochromatic one — that conveys depth extremely well. It’s pretty neat clearly seeing tiny specks of dust or lint present on surfaces when [Steve] demonstrates imaging things like coin cells.
There was a time when electronic engineering students studied the audio CD, for all its real-world examples of error correction and control systems. There’s something to be found in the system still for young and old though, and thus we were intrigued when we saw [Peter Monta] reading the data from a CD using a microscope.
CDs encode data as so-called pits and lands in a spiral track across a metalised surface, with a transition from pit to land signifying a logic 1 and a missing transition signifying a 0. Reading a section of the raw data is achieved in the first part of his write-up, but in the next installment he goes further into retrieving more data through stitching together microscope pictures and writing some code to retrieve data frames. He’s not quite at the audio playback stage, but he’s planning in the future to spiral-track a full image to rip an entire disc.
There are plenty of CD drives around to read audio the conventional way, but the techniques here still find a use where less ubiquitous media has to be read. In the last decade for example there was an effort to read the BBC Domesday Project from the 1980s, as it became clear that few of the original readers survived in working order.
Laser scanning microscopes are useful for all kinds of tiny investigations. As it turns out, you can build one using parts salvaged from a Blu-ray player, as demonstrated by [Doctor Volt].
The trick is repurposing the optical pickup unit that is typically used to read optical discs. In particular, the build relies on the photodiodes that are usually used to compute focus error when tracking a disc. To turn this into a laser scanning microscope, the optical pickup is fitted to a 3D printed assembly that can slew it linearly for imaging purposes.
Meanwhile, the Blu-ray player’s hardware is repurposed to create a sample tray that slews on the orthogonal axis for full X-Y control. An ESP32 is then charged with running motion control and the laser. It also captures signals from the photodiodes and sends them to a computer for collation and display.
[Doctor Volt] demonstrates the microscope by imaging a small fabric fragment. The scanned area covers less than 1 mm x 1 mm, with a resolution of 127 x 127, though this could be improved with finer pitch on the slew mechanisms.
Hackers frequently find themselves reverse-engineering or interfacing to existing hardware and devices, and when that interface needs to be a physical one, it really pays to be able to take accurate measurements.
This is easy to do when an object is big enough to fit inside calipers, or at least straight enough to be laid against a ruler. But what does one do when things are complex shapes, or especially small? That’s where [Cameron]’s DIY digital optical comparator comes in, and unlike commercial units it’s entirely within the reach (and budget) of a clever hacker.
The Comparatron is based off a CNC pen plotter, but instead of a pen, it has a USB microscope attached with the help of a 3D-printed fixture. Serving as a background is an LED-illuminated panel, the kind useful for tracing. The physical build instructions are here, but the image should give most mechanically-minded folks a pretty clear idea of how it fits together.
With the advent of streaming services, plenty of people are opting to forego the collection of physical media. In turn, there are now a lot of optical drives sitting unused in parts bins and old computers. If you’d like something useful to do with this now-obsolete technology, you can have a try at turning one into a laser microscope.
This build requires two DVD pickups. By scanning once horizontally and once vertically and measuring the returning light from the DVD laser, an image can be created. For this build, the second pickup is used to move the object itself. The entire device is controlled by an Analog Discovery 2, although this principle could be ported to other microcontroller platforms. Thanks to the extremely fine laser in a DVD and the precise movements of the motors found in the control machinery, the images obtained using this method have the potential to be more detailed than comparable visible light microscopes.
While this isn’t quite scanning electron microscope territory, it’s good enough to clearly image the internal workings of a de-capped integrated circuit. Something like this could be indispensable for reverse-engineering ICs or troubleshooting other comparably small electronics, with resolutions higher than can typically be obtained with visible light microscopes. We’ve even seen similar builds in the past which build microscopes like this as dedicated lab equipment.