BODY DUST: Feasibility study on signal transmission for sub-100μm-size active wireless biosensors

In this thesis, I discuss about the feasibility on creating an UltraSound (US) communication circuit to wirelessly 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 µm) in order to mimic the typical size of a larger blood cell (diameter around 30 µm for white cells) and so, to support free circulation of the cube in human tissues. The second constraint came from the low-power consumption request, with the energy provided by an external US base station. During the discussion I present the results of the feasibility study on the possibility to design an architecture for a data transmission transponder by using a 0.18-µm CMOS process, with sub-10 µW of power consumption and a total chip area of 43x44 µm2. Concluding I also discuss about the limits of the designed system and the needed for further improvements toward real applications in Body Dust diagnostics.