A miniaturized autonomous microsystem for hydrogen gas sensing applications

This paper presents a fully integrated, ultra-low power microsystem that is used for hydrogen gas sensing in an autonomous wireless sensor node. The proposed circuit harvests solar energy from a micro-power photovoltaic module to measure temperature and hydrogen concentration and transmits the measured value using wireless data transmission. A rechargeable NiMH microbattery is used to store harvested energy. Photovoltaic module charges this microbattery, using a highly area- and power-efficient power management circuit. In order to measure hydrogen concentration, conductance change of a miniaturized palladium nanowire sensor is measured and converted to a digital signal with 12-bit resolution, using an area-efficient readout circuit. The proposed microsystem has been implemented in a 0.18μm CMOS process and occupies a core area of only 0.47mm2. This circuit features a low current consumption of 200nA for power management circuit and an additional 1.1μA for sensor interface circuit. It operates with low power supply voltage in the 0.8V to 1.6V range.

[1]  Martin Steglich,et al.  Core–shell heterojunction solar cells on silicon nanowire arrays , 2012 .

[2]  M. Kayal,et al.  New Error Amplifier Topology for Low Dropout Voltage Regulators Using Compound OTA-OPAMP , 2006, 2006 Proceedings of the 32nd European Solid-State Circuits Conference.

[3]  Gabor C. Temes,et al.  Theory and applications of incremental ΔΣ converters , 2004, IEEE Trans. Circuits Syst. I Regul. Pap..

[4]  Patrick Merken,et al.  Ultralow-power hydrogen sensing with single palladium nanowires , 2009 .

[5]  L. Benini,et al.  Photovoltaic cell modeling for solar energy powered sensor networks , 2007, 2007 2nd International Workshop on Advances in Sensors and Interface.

[6]  Erik Puik,et al.  Ultra low power temperature compensation method for palladium nanowire grid , 2010 .

[7]  Kofi A. A. Makinwa,et al.  A CMOS smart temperature sensor with a 3σ inaccuracy of ±0.1°C from -55°C to 125°C , 2005, IEEE J. Solid State Circuits.

[8]  Marc Pastre,et al.  A solar battery charger with maximum power point tracking , 2011, 2011 18th IEEE International Conference on Electronics, Circuits, and Systems.

[9]  Marc Pastre,et al.  A fully integrated solar battery charger , 2009, 2009 Joint IEEE North-East Workshop on Circuits and Systems and TAISA Conference.