A 200 um by 100 um Smart Submersible System With an Average Current Consumption of 1.3 nA and a Compatible Voltage Converter

Dominic Funke, Philipp Hillger, Jürgen Oehm, Pierre Mayr, Lukas Straczek, Nils Pohl, John S. McCaskill

IEEE Transactions on Circuits and Systems I: Regular Papers, vol. 64, no. 12, pp. 3013-3024, December 2017; DOI: 10.1109/TCSI.2017.2750905


In this paper, we present a novel microscale “Smart Dust” type system designed to operate in aqueous solutions, with a volume of 200 μm × 100 μm × 35 μm, called a lablet. The lablet contains a 20 Hz low-power clock generator, a sensor, electric actuators, and a simple finite state machine to implement a predefined response to the sensor input. It is designed to be rechargeable and to communicate via local contacts through aqueous solution either between lablets or with a docking station chip. The system operates with supply voltages ranging from 0.3 to 1.8 V and is thus suitable to be supplied from a capacitor with decreasing voltage. An input rectifier allows powering the lablet independent of polarity. The average current consumption of the system was measured to be 1.3 nA when supplied from a capacitor with an initial voltage of 1.8 V. The small system scale allows the investigation of “pourable electronics”, a concept where large quantities of microsystems are deployed within a chemical solution to perform a predefined task. Several lablets have been designed and fabricated in a standard 180nm CMOS process and the electrical functionality has been verified by contacting the lablet electrodes with multiple probe needles. In order to use low voltage energy sources to supply the lablet, a voltage up-converter has been designed which is small enough to fit on the lablet.