Looking for waves to detect a specific material exclusively

[physior]

hello!

is there a material or substance that can be detected using some kind of waves (magnetic, electromagnetic, ultrasound, infrared, whatever, etc)
with extreme specificity (ie. no other materials or substances are to be mistaken)
with extreme sensitivity (ie. a nanometer of that material or substance can be distinguished from two nanometers)
and where the waves that detect it can penetrate most materials and detect the material or substance we are talking about beneath most materials regardless of the thickness

is there any 'material/substance and waves' couple that satisfies these conditions?

thanks!

 

[PeterDonis]

is there any 'material/substance and waves' couple that satisfies these conditions?

I don't know of any. Your requirements seem very strict, and not really compatible with one another. In particular, the "regardless of thickness" requirement and the "extreme sensitivity" requirement seem virtually impossible to satisfy at the same time.

 

[e.bar.goum]

By requiring extreme position resolution "a nanometer of that material or substance can be distinguished from two nanometers", you get in trouble. (unless you meant "nanogram")

If you relax that a bit, but still require extreme *abundance* sensitivity, with extreme specificity, there are a few techniques that come to mind - Accelerator Mass Spectrometry gives you extreme sensitivity -- you are talking about sensitivities on the order of 10^-16 -- literal atom counting, and it is certainly bulk, but you invariably destroy what you are looking so it doesn't have total utility. Most results are also relative to another ion. Isobars are also a problem, but in a lot of cases, if you're clever, you can deal with them.

If you're interested in ppm levels, you have a lot more options - neutron activation analysis is good if you don't mind making your material radioactive for some time. PIXIE is essentially non-destructive. Rutherford Back-scattering gives you information about the bulk. Neutron scattering is also good for a few centemeters, but I couldn't tell you what the sensitivity is. I suspect it's a matter of how long you count for.

Basically, there are a bunch of options, but you've got to pick the right one for the job.

 

[physior]

can't I just scan things for magnetic distortions and detect a material that distorts magnetism in a specific manner?
or if magnetic waves cannot penetrate things, maybe them radiowaves? or something other?

 

[russ_watters]

The method of detection depends on what you are trying to detect. Steel submarines, for example, are detected using magnetism.

 

[physior]

I alraedy said that I am trying to detect a material or substance that can be detected by waves that pass through most things!
eg, pass through water, flesh, bone, wall, metal if possible!

 

[physior]

for example, can raman spectroscopy see inside things? and does it have sensitivity to see small traces of a specific substance?

 

[physior]

ok, let's find waves that can see through things, are there any?

 

[Bystander]

Do you have something specific in mind? Niven's "deep radar?" Neutrino shadows? Gravity waves?

 

[physior]

I want to detect an item that passes through a detector
I can patch anything to that item
but the detector should be able to detect it even if it is inside a pocket or between books or inside a metal box (ok, not the latter if it's not possible)

 

[Bystander]

I want to detect an item that passes through a detector

We gathered that much --- you want to tag elephants with radioactive bowling balls? Minnows with radioactive iodine? Merchandise from the local "Big Box" to catch shop lifters? Hi-mu 80 in explosives for mine detectors? Something someone's lost? Tag things to track people/animals/vehicles?

 

[physior]

Merchandise from the local "Big Box" to catch shop lifters

 

[Bystander]

They've figured out how to kill the inventory control tags? So you need a new marker that can be "killed" or "cleared" at the scanner to let paying customers out --- oh, wow. Or, a scanner at the door that counts a particular sale, as it's leaving, and compares it to register "ticket." Got it. Good problem to play with --- and we want it "unspoofable."

Edit: Going to have to have the ticket in hand to get out of the store, aren't we.?

 

[physior]

I don't understand you, is this some kind of banter?

 

[Bystander]

No. I'm just rephrasing the problem in my mind, and maybe for some others following the thread. You've set us a "poser" in terms of what is "state of the art" for both the store, and the "discount shoppers." It's going to take a little thinking.

 

[PeterDonis]

I want to detect an item that passes through a detector
I can patch anything to that item
but the detector should be able to detect it even if it is inside a pocket or between books or inside a metal box (ok, not the latter if it's not possible)

The specifications you give in your OP are a lot more stringent than this use case implies. Is the item really going to be as small as one nanometer? (Do you know how small one nanometer is?) Do you really need detection through most materials regardless of the thickness? (You realize that implies detection through, say, a foot or a hundred feet or a mile of material, right?)

 

[physior]

the item is not going to be a nanometer, but the MARK on it is going to be that, the mark with that specific detectable substance

yes, I need detection of that specific substance regardless thickness of materials, but thickness won't be more than 1-2 meters

 

[davenn]

and why cannot you use the current RFID tagging systems ?EDIT ... oops not likely to work through metal, but I can't think of anything else that would either

 

[PeterDonis]

the MARK on it is going to be that, the mark with that specific detectable substance

How are you planning to make nanometer-sized marks with a specific substance? Once again, do you realize how small a nanometer is?

 

[physior]

ok, if not nanometer, definitely millimeter

 

[PeterDonis]

if not nanometer, definitely millimeter

In other words, a million times larger than a nanometer. That makes a big difference.

 

[russ_watters]

So you want to detect the mark, not the object? What is the mark made of?

Do you really not recognize how vague your description of your specs is?

 

[physior]

the mark can be anything! this is what I am trying to figure out, what material the mark needs to be and what waves I would need to use

 

[russ_watters]

Well, in that case I'd mark it with Pu 239. Then you can use a passive detector.

 

[physior]

no radioactive stuff! nothing harmful!
from my extended research, RFID seems interesting
can it do that?

 

[russ_watters]

I really have no idea. You said in your previous post that it could be anything, now you say there are limits. I'm not sure an RFID can be made as small as 1mm though.

Again, you'll get better answers if you become a lot clearer about what you are trying to do.