Overall plausible design. Main issue is the bluetooth antenna. An ideal antenna has a length in the same order of magnitude as the wavelength - typically 1/2, 1/4 or rarely 1/8 of the wavelength. The wavelength of bluetooth (2.4 GHz) is 12.5 cm or 1.24*10^-1m The antenna displayed in this diagram is about half the diameter of a red blood cell and as such about 4 µm or 4*10^-6m. A factor of 31250 to one. This has an effect of antenna efficiency. A smaller antenna size can be used but at a cost to bandwidth and energy requirements. You would need a signal with roughly 360000 times the amplitude to achieve the same emitting power as a normal lambda/4 bluetooth antenna. transmitter power however increases with the square of the amplitude. To achieve a typical bluetooth max Tx power of 1000 mW (30dBm) with a single nanite - This nanorobot would need to drive that antenna with the power of 100 Megawatt --- This seems unreasonable, unless a nuclear power source is used -- and also rises the question where 100 Megawatt of waste heat could be dumped within living tissue without cooking incineratingevaporating it.
One way around this is load spreading, using not one but many nanites- either physicaly connected or as a phased array. In theory a "string" of only around 2000 nanites is needed to reach a reasonable antenna length or phased array. The first would be pretty straightforward to implement, but would require the nanites to physically touch for the length of any transmission. For a phased array they remain independent but form a virtual array. This is possible, however then a second, local communication channel is needed to synchronize the phase-shifts between the participating nanites and reconstruct the original signal from the amplified differences in reception of all partaking nanites. This would require significant communication bandwidth at ultra stable low latency (however only over the relatively small distance of around 6cm - within tissue)
I would go for the second approach, but I am really curious how the synchronization between nanites would work.
Overall plausible design. Main issue is the bluetooth antenna. An ideal antenna has a length in the
I guess you know more about signals. Couldn't something like Tesla's theories about sending energy and information in electromagnetic waves be used and each drone be a repeater of the signals and generate a kind of "hive mind"? Or perhaps the design of the shape of the drones could be changed, so that it is more like an elongated disk or a rhombus or a cylinder, so that the entire length of the drone's body could be an antenna.
But what makes me doubt is this system of "recharging the battery by taking advantage of excess heat." It is something similar to what happens with spaceships... and living body: you need the heat to go away quickly, in a body the conduction of heat would be faster than in the vacuum of space, but the body is already a hot environment. Also, you can't just exploid or take advantage of heat... heat is energy converted into heat, in order to use that energy you need to convert it back into a form of energy that you need (that's why heat is always released as waste), heat can be used to evaporate water for example and thus make a steam engine converting that heat energy into mechanical energy that they then convert into electricity. But heat can't just be automatically exploited and the ways to recycle that energy generated as waste are slower than just expelling it, and if you need to expel heat, if you don't do it you will overheat quickly. It would be more convenient to have an energy source and a design so efficient that it does not generate energy losses in the form of heat. A living body is an extremely inefficient machine in terms of energy, with all the energy it wastes in the form of heat, although the body needs to be kept at a certain temperature to keep functioning well because it is an ecosystem as well as a machine (cells, benign bacteria in the intestines, etc.).
Another thing that makes me doubt is the size. Drones being as big as a cell... that's pretty big, you can't have too many of those because I suppose they would create obstructions, right?; and to do significant things quickly you need quite a big number. Perhaps viruses like HIV should be taken as an example, since they are basically not living organisms like bacteria but are self-replicating machines of nature (something like identical twins are the clones of nature). I've seen something about the possibility of making nanobots even the size of molecules, but of course... the smaller the simpler it will be...
I guess you know more about signals. Couldn't something like Tesla's theories about sending energy a
a good size is the size of a bacteria. Much much smaller than body-cells but still full fledged nanomachines with its own fully operational metabolism - doing a nanobot in microbe-size would be possible and avoid the obstruction/space issues you'd have with a bot the size of tissue cells.
But being that tiny brings problems with energy supply, communication and transport. Transport is less of an issue if you just have enough of them everywhere you can just use the blood-stream and lymph stream and maybe augment the flow if its too low with propulsion.
power - again to receive power over the air tesla-style you need matching antennas, and electromagnetic fields in the wavelength of the robot do not go through water - and as such not through tissue - which is a problem. light works, especially locally to communicate with neighboring nanobots, as light passes through tissue quite well (could be infrared to avoid glowing in the dark ;) )
that would also allow the formation of phased arrays across larger areas to communicate with bluetooth, you just need to sync with LEDs
so - how to power all of that. the easiest would actually be chemical. Living bodies themselves provide chemical power to the cells, the simplest way to provide bots with power would be to just tap into the existing supply route - and then have each bot accumulate and store some energy for later if higher output is needed.
a good size is the size of a bacteria. Much much smaller than body-cells but still full fledged nano
The reason the nanobots are nearly the size of red blood cells is because of the onboard power and, more importantly, onboard COMPUTER. I figured they would stay in the bloodstream, just small enough to fit through capillaries.
The reason the nanobots are nearly the size of red blood cells is because of the onboard power and,
