Author(s)Koshro Pour, Naser; Kayal, M.; Jia, G. is set up to detect hydrogen gas concentration in the low ppm range and over a broad temperature range using a low power sensing interface circuit. Using Telran TZ1053 radio to send one sample measurement of both temperature and H 2 concentration every 15 seconds, the average and active power consumption for the SiNAPS mote are less than 350nW and 2.1 µW respectively. Low-power miniaturised chemical sensors of liquid analytes through microfluidic delivery to silicon nanowires are also presented. These components demonstrate the potential of further miniaturization and application of sensor nodes beyond the typical physical sensors, and are enabled by the nanowire materials platform.

This paper presents an ultra-low power, fully integrated solar energy harvester circuit for autonomous microsystems. The proposed circuit harvests solar energy from a micro-power photovoltaic module and stores the harvested energy in a miniaturized thin film Li-Ion microbattery, using a highly area-and power-efficient power management circuit. As neither inductor, nor large pumping capacitors have been used in this circuit, it occupies less area comparing to conventional inductive and switched-capacitor DC-DC converters. In addition, thanks to low power design of this circuit, it achieves more than 94% efficiency during battery charging. Even under reduced light intensity, when the harvested energy is only a few tens of microwatts, more than 92% efficiency is achievable. The proposed microsystem has been implemented in a 0.18µm CMOS process and occupies a core area of only 0.12mm 2 . This circuit features a low power consumption of 270nW in average.