Talk:Discarded devices
From Wise Nano
Radio signal by Brett Bellmore 12:47, 25 Oct 2004 (CDT)
It's relatively difficult for an object to radiate electromagnetic waves of a wavelength many times their own size, and for artifacts the size we're discussing, it would be highly energy intensive to radiate enough to be detected. As well as the fact that "radio", comparatively long wavelength radiation, doesn't facilitate precisely locating extremely small objects.
I'd suggest tagging them with some kind of narrow floresence response to a precise wavelength of light. This would enable a cleanup bot to simply scan the enviroment with a carefully tuned laser, and home right in on debris.
Hypothetically, this might even be acomplished by incorporating the right lattice defects into the diamonoid.
(no topic) by Matt 19:59, 25 Oct 2004 (CDT)
I recomend the RFID article on wikipedia.org. It states that passive RFID tags have broadcast ranges between few mm and several meters. They don´t need a battery to operate, a current is induced by the RF scan. As for size: All you need is a long antenna (maybe one or several CNTs?) wound up in a spiral form and some simple (molecular!) ICs to return the device´s ID. At the moment, the smallest RFID tag covers an area of 0,25 mm², i.e. about 0,5 mm on a side, and with thickness of a sheet of paper, at 15 to 20 feet range. I don´t know what´s the theoretical lower size limit for such a tag, do yo have a source on this question? Is there a theoretical limit on how tight you can wind up such a compact antenna?
and for artifacts the size we're discussing
Granted, it probably doesn´t make much sense to have tags that are many times larger than the actual device; it might, however, not be completely senseless to have a millimeter tag on a micrometer or even nanometer device, if the device´s functionality is not limited by the tag. For example, the CO2 collecting molecules I mentioned in the article might be parallely strapped on a base plate containing an RFID tag for later retrieval.
Depending on how much the tags can be shrunk while still doing anything useful, they can at least be used for sub-mm devices, taking today´s limit as a permanent one. However, I doubt that we already have to stop there (then again, I´m just guesstimating).
As well as the fact that "radio", comparatively long wavelength radiation, doesn't facilitate precisely locating extremely small objects.
It wouldn´t have to be precise to work, I think. A cleanup robot just would have to know a rough device density (from the number of returning signals within a certain range) to decide whether it´s worth starting to vacuum in his area. Once it sucked up the devices together with the surrounding dirt (or water or whatever), it can channel the whole material through properly designed ducts/gates/filters/whatever and just pull out the devices, returning everything else.
Also, if a certain device class poses no particular long-term environmental threat, said threshold density can be set to a higher value, to just clean up the biggest mess and be economical. Depending on the device, the beacon signal and the threshold density can be adjusted to achieve a certain return ratio. If you want more devices back, e.g. because they might be dangerous or because they hold data, you just have to clean more thoroughly.
I'd suggest tagging them with some kind of narrow floresence response to a precise wavelength of light. This would enable a cleanup bot to simply scan the enviroment with a carefully tuned laser, and home right in on debris.
Good idea I guess. Please, add it to the possibilites, and everything else you thought of, too! Just a quick question: Would lasers work in a very dusty environment? The laser beam might be scattered too much to be useful, whereas radio would be unaffected, or not?
