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For the purposes of this question, let's use the definition of nanotechnology from the tag wiki excerpt: "technology that works with sizes of less than 100 nanometres".

An EMP can vary in frequency range, but Wikipedia gives "DC to daylight" as excluding infrared and shorter wavelengths. It also gives the range for infrared as 300 GHz (wavelength 1 mm) to 700 nm (frequency 430 THz, or 430,000 GHz). It also states long-wavelength infrared as having a wavelength of up to 15,000 nm, which corresponds to a frequency of 20 THz. (Remember: wavelength is the inverse of frequency.) If we take the longer-wavelength boundary of long-wavelength IR to be the upper bound of "DC to daylight", this means that the pulse has frequency components ranging from basically 0 to 20 THz.

In order to induce a voltage in an antenna (whether intentionally designed as an antenna or not), the antenna must be a reasonable fraction of a wavelength. If the antenna is too short, the EM field simply doesn't have time to sufficiently interact with the conductor to induce a voltage.

Even at 20 THz, 100 nm represents 1/150 of a wavelength, which is pretty far below what you'd expect to need for a reasonably efficient antenna, which at least for much lower frequencies you might begin to see somewhere around ten times that size (in terms of wavelengths).

Let's also rule out a direct EMP strike. (Let's face it, if someone hits your device with what is basically a lightning strike at point blank range, few things will survive unscathed.)

Given all this, would nanotechnology likely be affected by an EMP? Why or why not? What factors would contribute to susceptibility or non-susceptibility to EMP damage in a nanotechnology scale device?

I'm not tagging this hard-science, but the harder the science in answers, the better.

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    $\begingroup$ EMP "frequency range"? What's that? Do you understand how EMP weapons work? $\endgroup$ – AlexP Aug 20 at 20:38
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    $\begingroup$ @AlexP Did you read past those words that you quoted? I linked to the exact Wikipedia article you link to in your comment within that same sentence. Wikipedia provides the elaboration of "DC to daylight" giving the relevant values as used in my question here, and the Wikipedia article even uses those words as the relevant section heading. $\endgroup$ – a CVn Aug 21 at 6:24
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    $\begingroup$ Do you really need an EMP? Nanomachines are extremely vulnerable to most EM radiation in general; a low intensity UV or gamma burst would be completely harmless to humans while destroying any nanomachine; even a bit of heating would be enough. Heck, we use that approach to kill bacteria and viruses. You're not going to damage an individual isolated nanomachine with an EMP, strictly speaking - but the source of that blast might do the job as a side-effect of how it creates the EMP. The real problem is how the deadly radiation can reach the machines... $\endgroup$ – Luaan Aug 21 at 7:23
  • $\begingroup$ @Luaan "really need an EMP" might be stretching it, but if I wasn't interested in an answer to the question I'm asking, then I either would have asked a different question, or none at all. $\endgroup$ – a CVn Aug 21 at 16:07
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Let's distinguish between nanomachines (which are self-contained structures on the nano scale) and nanodevices (which could be just parts in a larger machine).

  • EMP weapons work by inducing damaging voltage in electric conductors. A nanomachine is very very small; let's say that the EMP comes with a humongous 100 kV/m. (For comparison, the insulating ability of air is about 1000 kV/m tops.) (For another comparison, actual EMP weapons tests achieved about 10 kV/m.) Let's say that the nanomachine is one micrometer long. (That's 1000 nanometers, but hey, let's make 'em big.) This means that the EMP will induce a maximum of a measly 0.1 V in the longest conductor in the nanomachine. Whether a sudden "shock" of 0.1 V is damaging to the nanomachine depends on how the nanomachine works. All I can say is that I've never heard of a semiconductor diode with a threshold voltage of less than 0.2 V.

  • On the other hand, a nano-scale device which is just a small part of larger machine is obviously vulnerable to EMP weapons. Think of an itsy-bitsy transistor in the ARM processor of a mobile phone plugged in the charger plugged in the power outlet connected to a thousand-mile long overhead line in the national power grid. If an EMP comes that transistor is gone.

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    $\begingroup$ I see your point, but I don't think that determining that's it's 'only' .01V makes the problem go away. At that point I think it depends on how much power the nanomachine is designed to be able to handle, which in turn depends on how much power it needs to do whatever it's doing. It's reasonable to assume that a nanomachine that's only designed to need .01V to operate is probably going to suffer if it gets a power surge of ten times its designed operating limits, and if you're designing nanomachines you're only going to design it to handle conditions it's likely to encounter. $\endgroup$ – Morris The Cat Aug 20 at 22:04
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    $\begingroup$ @MorrisTheCat: Voltage is not power. If the voltage induced by the EMP is lower than the threshold of the gates then it won't have any effect -- zero power. I don't know how low can the operating voltage of a processor be, but I would really be (very pleasantly!) surprised if it can be made much lower than 0.5 V, even in principle. (But anyway that's why I hedged saying that it depends on how the nanomachine works.) $\endgroup$ – AlexP Aug 20 at 23:16
  • $\begingroup$ "Operating voltage" is safe as long as you apply it where expected... Example: my Christmas lights may operate at 220 Volts, meaning that It is safe to apply 220 volts to a large strip of leds. This can be true, but also it can be true that applying a tenth of that to a single led will cause it to explode... $\endgroup$ – ntg Aug 21 at 13:50
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BIggest problem with your question:

"technology that works with sizes of less than 100 nanometres".

That covers an awful lot of things, including the logic gates in the microprocessors that ultimately run the thing you used to post the question. Those nanoscale devices are obviously vulnerable to EMP, because they communicate with the outside world via the medium of long conductors, which can act as antennae, and they're powered by other even longer conductors. Conversely, the cells you're presumably made of also contain many nanoscale components and large-scale conductive networks, but they're pretty robust to all sorts of electrical and electromagnetic abuse. People have survived lightning strikes and actual nuclear EMP after all.

Whether any other nanoscale devices would be vulnerable to EMP depends very much on where they are, what they're made of, what they do and how you make them do it. If a blob of nanowhatevers is conductive and macroscale (eg. they form a network) or is sufficiently close to something else that is, then sure, you could potentially toast em. If they're dispersed within some other resilient medium then they probably won't get zapped directly, but whatever is used to tell them what to do might well use macroscale electronic components, and if that gets wasted what use is the nanoscale part of the system?


With regards to your upper frequency limit though, far infrared... lots of things are vulnerable to being cooked, especially very small things that can't easily shed heat. Seems strange to include that sort of thing in a definition of EMP, but there you go.

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  • $\begingroup$ The reason why a microprocessor is vulnerable to EMP is that it's surrounded by lots and lots of relatively long wires, which can pick up the EM field and thereby have an induced voltage far in excess of the design specifications. Or are you arguing that a disconnected CPU, sitting in its box on a wooden table (or similar), would also be destroyed by an EMP? $\endgroup$ – a CVn Aug 21 at 6:27
  • $\begingroup$ @aCVn from my answer, "they're powered by other even longer conductors". However, any EM source that generates substantial amounts of microwaves will certainly disrupt an active CPU, though I couldn't tell you whether it would cause lasting damage or cripple an inactive CPU. It would be possible, certainly. High-altitude EMP (or the effects of things like Carrington events) are a subset of EMP in general. $\endgroup$ – Starfish Prime Aug 21 at 6:39

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