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
