An autonomous microsystem for environmental and biological data gathering

This paper reports a 0.15cc multi-sensor microsystem for autonomously sensing and storing environmental and biological data. The microsystem comprises a custom sub-mW sensor-interface chip, a mixed-signal microcontroller, and a nonvolatile memory. These components, together with on-board pressure/temperature/humidity sensors and off-board strain gauges and neural/EMG electrodes, accomplish multi-domain data acquisition/storage with very low power (<50μW for 1Hz capacitive-sensor readings). The system is integrated on a micromachined silicon platform that implements through-wafer interconnects, solder-based microconnectors, and recessed cavities for chip-stacking. The platform allows microsystem realization in 9.5mm × 7.6mm × 2.0mm (0.15cc) (<0.5cc with a lithium battery), representing a very high level of miniaturization for systems of this complexity.