A Very Different ‘Hot Or Not’ Application For Your Phone

Radioactivity stirs up a lot of anxiety, partially because ionizing radiation is undetectable by any of the senses we were born with. Anytime radiation makes the news, there is a surge of people worried about their exposure levels and a lack of quick and accurate answers. Doctors are flooded with calls, detection devices become scarce, and fraudsters swoop in to make a quick buck. Recognizing the need for a better way, researchers are devising methods to measure cumulative exposure experienced by commodity surface mount resistors.

Cumulative exposure is typically tracked by wearing a dosimeter a.k.a. “radiation badge”. It is standard operating procedure for people working with nuclear material to wear them. But in the aftermath of what researchers euphemistically call “a nuclear event” there will be an urgent need to determine exposure for a large number of people who were not wearing dosimeters. Fortunately, many people today do wear personal electronics full of components made with high purity ingredients to tightly controlled tolerances. The resistor is the simplest and most common part, and we can hack a dosimeter with them.

Lab experiments established that SMD resistors will reveal their history of radiation exposure under high heat. Not to the accuracy of established dosimetry techniques, but more than good enough to differentiate people who need immediate medical attention from those who need to be monitored and, hopefully, reassure people in neither of those categories. Today’s technique is a destructive test as it requires removing resistors from the device and heating them well above their maximum temperature, but research is still ongoing in this field of knowledge we hope we’ll never need.

If you prefer to read about SMD resistor hacks with less doomsday, we recently covered their use as a 3D printer’s Z-axis touch sensor. Those who want to stay on the topic can review detection hacks like using a single diode as a Geiger counter and the IoT dosimeter submitted for the 2017 Hackaday Prize. Or we can choose to focus on the bright side of radioactivity with the good things made possible by controlled artificial radioactivity, pioneered by Irène Joliot-Curie.

[via Science News]

27 thoughts on “A Very Different ‘Hot Or Not’ Application For Your Phone

  1. “Radioactivity stirs up a lot of anxiety, partially because ionizing radiation is undetectable by any of the senses we were born with.”

    Till one get’s immersed in lots of it. Say a failed reactor.

    1. Indeed. But at a worst case of 2 significant events (earthquake AND tsunami), you end up with a few miles being radiocontaminated. Yeah, it sucks to say “humans cant go in here for the next X thousand years”.

      The converse is things like coal and oil. Just exactly how much pollutants do those pump out per year? How many people die because of those due to air quality, groundwater pollution, and other mass environmental effects?

      I’ll take my minuscule chance of radioactivity over widespread dead dino pollution.

      1. A properly built reactor unit, no corners/costs cut, would be resistant to most events, with bad consequences greatly minimized. And a great way to assure the quality of construction is to make the bean counters responsible for the approval of the projects to have their offices and work inside the nuclear plant.

        But hey, oil is a renewable source. We just need some dinos and a couple million years…

        1. “A properly built reactor unit, no corners/costs cut, would be resistant to most events, with bad consequences greatly minimized.” Except for the empirically determined fact that human beings are not actually capable of doing such things! Have you been watching too much fantasy television? Think of all we could do if we stopped being so lazy and invented time travel!

        1. Storage and spikiness of renewable resources (solar, wind, tide) are what makes nuclear look damned good. Its hard to crystallize sunlight or wind. And battery power densities well, suck, when compared to chains of carbon and hydrogen or of nuclear fuel.

          Nuclear has a nice decay rate that we know will be in 10, 20, 30 years. Effectively, when you know you have a absolute minimum load, you back it by nuclear fission. Eventually, we’ll be able to back it by fusion.

          1. There are multitudes of options to store energy. The density doesn’t matter for stationary storage. Storage isn’t a problem. Neither is generation. We could have a healthy mix of solar and wind generation connected to the existing power grid. If it’s not sunny somewhere, or windy, power can come from areas of the country where it is. We also need to overproduce. Don’t size a system only large enough to take care of our energy needs in the best conditions.

          2. Yes that’s the problem. And to make things worse, people try to sell us a degradation of electrical supply performance as “smart grids”. Basically an infrastructure to “ration” the power centrally instead providing it on demand when it is needed, as it is done in our today’s electrical grids.

          3. No, NiHaoMike, that’s the wrong way. We need methods to match supply to demand, like in the existing electrical grid. Anything else represents a degradation of supply quality. Do you really like that? Me not. And if we need nuclear plants to cover the demand, THEN BUILD THEM.

          4. I would like to see approaches to adapting demand to supply that focuses on turning stuff on if it’s the kind of load where more use at one time can reduce use at other times. Namely provide incentive to invest in cheap and reliable thermal storage for HVAC and hot water, the two biggest energy uses in most homes.

        2. Half true.
          Mining the precious metals and exotic elements needed for renewables has the same downsides as mining for coal or any other resource. Go take a google earth tour of precious metals mines (mountain view, CA, inner mongolia, Turkey / Ukraine / black sea russia). All those pretty colors in the dirt and streams are acidic metal laden pollution.

          That said it’s easier to contain pollution at a mine than at power plants scattered across the countryside or coming out of your car exhaust.

        3. Unfortunately it has other severe downsides: No sun in the night and in some winter seasons. Build a good nuclear plant, out of earthquake regions and don’t make crazy experiments like in Chernobyl. Then you havwe very save energy production.

  2. Given the level of truth people tell when asked if they dropped or wet their phones, I think it will be a little difficult to know with some confidence if they & the phones have been in a specific area.

  3. I always wondered if a solar cell could be used as radiation detector. If it responds to low energy visible light, it should work for far higher energy particles as well, I think.

  4. Cell phone camera can detect ionizing radiation, as it will result in more “random” stuck pixels in a photo, since the intensity would saturate the sensor at those pixel positions.

    Some black tape around a cellphone camera, and checking for a large amount of “white” pixels would do the trick in a pinch.

      1. Take a video or timelapse series. A few long exposure picture averaged every few minutes should be useful.
        Obviously this filters out soft radiation that can’t penetrate the lens or touch screen so the dirt and dust may be dangerous but you’ll have no idea. That’s not unique though so, probably not worth sweating.

    1. You’re absolutely correct, but those items don’t usually start out with source materials as pure as that for SMD resistor manufacture, and that purity helps build a good baseline. Secondly, those items aren’t always worn by people, and the goal is to use something that was worn on each person at the time of “the nuclear event”.

  5. Boy, when you start looking at the destructive uses for iphones that really opens up the door for a lot of things. You could start a call and duct tape your phone to a train rail and detect when a train comes by. If you have an excess number of warheads around you could do the same and tell if one went off. Lots of sacrificial uses.

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