Ultra-low Power MEMS Activity Sensor for Wireless Health Monitoring System

Abstract

This paper presents the design and implementation of a MEMS activity sensor operating at less than 50 nW for monitoring of the simple health conditions of animals, particularly of chickens. The developed MEMS activity sensor includes a piezoelectric microcantilever, a low power comparator integrated with a CMOS multi-step voltage reference generator, and a counter. This system enables the realization of a wireless sensor node to work continuously for more than two years using a 1.55 V button battery weighing 0.5 g.