There are many ways to detect stress in an individual. You can use self-reporting checklists, you could try and measure various vital signs like respiratory rate and pulse and infer things, or you could observe the levels of hormones like cortisol in the blood.

Or… you could pull some parts out of a Playstation 4, and get hacking. Edwin Hwu did precisely that, creating a device that can image the skin down to the nanometer and potentially even determine fine details about an individual’s health status. He came to Hackaday Europe 2026 to tell us all about it.

Look Closely

Edwin’s background is very relevant to this project. He worked in a research institute in Taiwan where he collaborated with the German National Metrology Institute, working on atomic resolution imaging on silicon wafers. When you’re doing sub-nanometer calibration work for the semiconductor industry, that’s serious stuff, as is the X-ray microscopy that Edwin has dived into. When it comes to looking at things at very tiny scales, he knows his stuff. He’s also done plenty of work on real-time cell culture monitoring, skin assessments, and even high resolution 3D printing. It’s a broad skill base that all fed into the project he came to Hackaday Europe to talk about.

There is a problem with optical microscopy that comes down to the diffraction limit of light—which means you can only image down to a resolution of around 1 micrometer. That’s why we use scanning electron microscopes for so many finer tasks, because the diffraction limit of electron beams is so much smaller. This allows the imaging of structures like carbon nanotubes or buckyballs, but with the limitation that the surface must be conductive and the imaging be done in a vacuum environment. A newer technology is the atomic force microscope (AFM), which involves using a very sharp probe with a tip of just 2-3 nanometers to actually touch molecules. This can be done without a need for a conductive surface or vacuum. When taking this approach to look at things on the nanometer scale, Edwin likens it to trying to poke a 1 euro coin with the tallest mountain on Earth. It’s a precise device with incredibly high resolution, but the average AFM costs half a million euros, and is incredibly bulky and slow at what it does. That is, unless… you find a way to build one on the cheap.

Some time ago, Edwin created an atomic force microscope using the optical head of a DVD player, achieving a resolution of 0.39 nanometers. With this build, it was possible to image a single strand of DNA. Edwin also talks about how he used simple piezoelectric buzzers to create an ultrafine scanner for this work. The piezo elements are used for actuation, since they can be controlled to make incredibly minute movements. The work developed to the point where DIY AFM kits were made available at a mere fraction of the cost of traditional laboratory-grade installations.

This work spawned a greater plan. Through his talk, Edwin explains how he figured out that e-waste gaming consoles could be turned into cutting-edge atomic force microscopes. Specifically, the Playstation 4 was the perfect candidate, with its high-end Blu-Ray optical head which is capable of reaching the diffraction limit of light. The Blu-Ray optical head is used to monitor the movement of the AFM probe, while scanning it is achieved with a piezo rig just like the earlier DVD-based build. It also has the benefit that the Blu-Ray hardware is built for higher data rates, meaning it’s possible to stream data from the optical head much faster for a quicker AFM scan. Edwin refers to his build as the HS-DAFM—for High Speed Dermal Atomic Force Microscope—since it’s 100 times faster than traditional laboratory atomic force microscopes.

The word “dermal” is important—because Edwin has put the build to use in examining skin nanotexture, for diagnostic purposes. His talk explains how, combined with machine learning systems, the tool can be used to investigate skin conditions and help in the diagnostic process. It’s also become useful from the perspective of cosmetics, and looking at how the skin looks at the nanoscale due to factors like aging and UV exposure. With the aid of machine learning tools, Edwin has found that it’s even possible to determine if someone has asthma with 75% accuracy, just from a skin scan. There is even an exploration of mental stress versus skin nanotexture, albeit in a very preliminary stage.

If you’ve ever wondered about the finer details of doing atomic force microscopy on the cheap, or how skin texture holds the secrets of so many health-related matters, Edwin’s talk is a great one. Sometimes thinking outside of the box and the limitations of commercial laboratory equipment can lead to wonderous things, as it did here!