A digital chip - an epidermal electronic system (EES) is in development which would be able to carry low resolution bio-chemical information in an artificial unit much smaller than current EEG or EMG equipment. The materials are the same as other bio sensors but ananoribbons allow it to sit on a 30 μm elastic polyester sheet, it's thickness makes it flexible and it only weighs 0.009g.
It uses a glue similar to the one in temporary tattoos and has been successfully programmed to pick up electronic signals on the forehead, chest and arms. Powering it is a problem and researchers are looking at battery technology and induction to run the unit. It currently uses a solar cell but the power is far too limited for the chip to provide in-depth information on it's own.
The device is only able to be worn temporarily as the body's natural chemical excretions begin to erode the fragile construction after 24 hours.