Exposing the Wi-Fi chip to gamma radiation. (Credit: Yasuto Narukiyo et al, 2026)
From outer space to down here on Earth, there are many places where ionizing radiation levels are high enough that they effectively bar access for humans, but also make life miserable for anything containing semiconductor technology. This is especially true for anything involving wireless communications, such as Wi-Fi. However, recently Japanese researchers have created a Wi-Fi chip that is claimed to be so radiation-hardened that it can be used even in gamma ray-rich environments, such as in the worst contaminated depths of the Fukushima Daiichi nuclear reactor.
The indicated dose exposure of 500 kilograys that the chip survived during testing is quite significant. A single gray (Gy) is the absorption of one joule of energy per kilogram of matter. In radiation therapy, a solid epithelial tumor can receive as much as 60 to 80 Gy in a single dose, for example.
The topic of boiling water is apparently a rather divisive topic, with plenty of strong opinions to go around on what is safe and the most efficient way to go about it. Thus in a new video [Cahn] sought to address the many comments that came in after his previous testing of electric kettles on either 12 VDC or 240 VAC.
What’s interesting about this whole topic is that at its core the overall efficiency of boiling water is simply a matter of calculating the energy input minus energy losses, with the remaining energy going into the water.
As we can see in the video, using a higher battery voltage doesn’t really change the efficiency of a 12 VDC kettle, but the higher current draw does manage to melt a fuse that can’t take the heat — requiring a 20 amp fuse instead of the 15 A one.
One change that does make a difference is how it’s connected. Replacing the thin gauge wiring and the attached cigarette lighter plug on the 12 VDC kettle with beefier cable and an Anderson plug made things run cooler, resulting in an efficiency bump of about 10%. This cut the time required to get the water boiling by around 6 minutes.
Added to this test were an induction hob and an iso-butane-powered Jetboil, both of which scored rather unimpressively. For the induction option it’s obvious that a lot of energy is wasted by having the pan radiate it away from the water, while burning iso-butane loses energy through the exhaust gases. Ultimately what you pick to boil water with should thus be mostly determined by convenience rather than sheer physics.
Electro-permanent magnets (EPMs) are pretty nifty concepts, and if you aren’t familiar with them, they are permanent magnets with the ability to be electrically switched on or off. Unlike an electromagnet — which maintains a magnetic field only while power is applied — an EPM can remain “on” even when power is removed. Want to see one work? There’s a video embedded below that shows one off, but if you’d like to know how they work, we have you covered.
Inside are two types of magnet, one of which is permanent and the other being a semi-hard magnet paired with an electromagnetic coil. A semi-hard magnet’s flux can be changed by exposing it to a strong enough magnetic field, and that’s the key to making it work.
Being able to electrically switch a permanent magnet on or off is a neat trick.
When both magnets work together, the EPM is “on” and acts like a permanent magnet. To turn the EPM off, the polarity of the semi-hard magnet is flipped with a short and powerful electromagnetic pulse, after which the two magnets oppose one another and more or less cancel each other out. So rather than generating a magnetic field, an EPM more accurately reconfigures it.
As intriguing as EPMs are, we haven’t really seen one properly in action until it was brought to our attention that [Dave Jones] of EEVblog tried one out last year. He received a Zubax FluxGrip EPM, which is intended for drone and robotic applications and can hold up to 25 kg. Watch [Dave] fire it up in the video (link is cued up to the 7:30 mark), it’s pretty interesting to see one of these actually work.
EPMs are not prohibitively expensive but they are not exactly cheap, either. But if a switchable magnet sounds up your alley and you can’t afford an EPM, consider an alternative “switchable” magnet design that works by momentarily canceling out a permanent magnet with a paired electromagnet. Unlike an EPM, it’s not a permanent switch but it would be enough to drop a payload.
Keeping your filament safely away from moisture exposure is one of the most crucial aspects of getting a good 3D print, with equipment like a filament dryer a standard piece of equipment to help drive accumulated moisture out of filament prior to printing or storage. Generally such filament dryers use hot air to accomplish this task over the course of a few hours, but this is not very efficient for a number of reasons. Increasing the vaporization rate of water without significantly more power use should namely be quite straightforward.
The key here is the vapor pressure of a liquid, specifically the point at which it begins to transition between its liquid and gaseous phases, also known as the boiling point. This point is defined by both temperature and atmospheric pressure, with either factor being adjustable. In a pressure cooker this principle is for example used to increase the boiling temperature of water, while for our drying purposes we can instead reduce the pressure in order to lower the boiling point.
Although a lower pressure is naturally more effective, we can investigate the best balance between convenience and effectiveness.
Have you ever wanted to see the computers behind the first (and for now only) man-made objects to leave the heliosphere? [Gary Friedman] shows us, with an archived tour of JPL building 230 in the ’80s.
A NASA employee picks up a camcorder and decides to record a tour of the place “before they replace it all with mainframes”. They show us computers that would seem prehistoric compared to anything modern; early Univac and IBM machines whose power is outmatched today by even an ESP32, yet made the Voyager program possible all the way back in 1977. There are countless peripherals to see, from punch card writers to Univac debug panels where you can see the registers, and from impressive cabinets full of computing hardware to the zip-tied hacks “attaching” a small box they call the “NIU”, dangling off the inner wall of the cabinet. And don’t forget the tape drives that are as tall as a refrigerator!
We could go on ad nauseum, nerding out about the computing history, but why don’t you see it for yourself in the video after the break?
Although GNSS systems like GPS have made pin-pointing locations on Earth’s sphere-approximating surface significantly easier and more precise, it’s always possible to go a bit further. The latest innovation involves strapping laser retroreflector arrays (LRAs) to newly launched GPS satellites, enabling ground-based lasers to accurately determine the distance to these satellites.
Similar to the retroreflector array that was left on the Moon during the Apollo missions, these LRAs will be most helpful with scientific pursuits, such as geodesy. This is the science of studying Earth’s shape, gravity and rotation over time, which is information that is also incredibly useful for Earth-observing satellites.
Laser ranging is also essential for determining the geocentric orbit of a satellite, which enables precise calibration of altimeters and increasing the accuracy of long-term measurements. Now that the newly launched GPS III SV-09 satellite is operational this means more information for NASA’s geodesy project, and increased accuracy for GPS measurements as more of its still to be launched satellites are equipped with LRAs.
Ionizing radiation damage from electrons, protons and gamma rays will over time damage a CMOS circuit, through e.g. degrading the oxide layer and damaging the lattice structure. For a space-based camera that’s inside a probe orbiting a planet like Jupiter it’s thus a bit of a bummer if this will massively shorted useful observation time before the sensor has been fully degraded. A potential workaround here is by using thermal energy to anneal the damaged part of a CMOS imager.
The first step is to detect damaged pixels by performing a read-out while the sensor is not exposed to light. If a pixel still carries significant current it’s marked as damaged and a high current is passed through it to significantly raise its temperature. For the digital logic part of the circuit a similar approach is used, where the detection of logic errors is cause for a high voltage pulse that should also result in annealing of any damage.
During testing the chip was exposed to the same level of radiation to what it would experience during thirty days in orbit around Jupiter, which rendered the sensor basically unusable with a massive increase in leakage current. After four rounds of annealing the image was almost restored to full health, showing that it is a viable approach.
Naturally, this self-healing method is only intended as another line of defense against ionizing radiation, with radiation shielding and radiation-resistant semiconductor technologies serving as the primary defenses.
