Sensors for Kinetic Energy Measurement Operating on “Zero-Current Standby”

The ever increasing need to extend battery life in IoT devices, self-powered sensors, and autonomous nodes highlights the need to reduce energy consumption as much as possible. One of the main issues still not fully addressed is the reduction of power consumption of sensors and measurement systems in standby mode, which represents a significant amount of the total power dissipation. In fact, nowadays, despite the continuous efforts, standby power is still far from being negligible. This paper exploits a new approach named "zero-current standby" to tackle this issue; moreover, due to the fact that the transducer implements kinetic-to-electrical energy conversion, a sensor that performs kinetic energy measurements is obtained and characterized. The proposed solution goes beyond the concept of the standby state itself, as it can actually be applied to appliances turned OFF. The design of a piezoelectric-based sensor able to measure kinetic energy is discussed in this paper. The proposed device will also allow zero-energy standby operation, with vibrations acting as trigger for sensor activation and data transmission via Wi-Fi. Numerical analysis, laboratory characterization, and experimental results of a complete working prototype are presented here, demonstrating both the suitability of the approach proposed and the improvement with respect to conventional strategies.