  In this paper, we discuss the feasibility of creating an UltraSound (US)
communication circuit to wireless transmit outside the body diagnostic
information from multiplexed biosensors chip built on the top layer of a
drinkable CMOS Body Dust cube. The system requires to be small enough (lateral
size of less than 100 um) to mimic the typical size of a larger blood cell
(diameter around 30 um for white cells) and so support free circulation of the
cube in human tissues. The second constraint came from the low-power
consumption requirement, with the energy provided by an external US base
station. The results of the feasibility study demonstrate the possibility to
design an architecture for a data transmission transponder by using a
0.18{\mu}m CMOS process, with sub-10 uW of power consumption and a total chip
area of 43x44 um^2. The paper also discusses the limits of the designed system
and the need for further improvements toward real applications in Body Dust
diagnostics.
