Micro Energy Harvesting for IoT Sensors

Wireless IoT devices are becoming increasingly popular both for consumers and industry. Through modern power efficiency we've experienced a remarkable stride in battery life, facilitating the introduction of these products to the market. Nevertheless, the predominant weakness of wireless sensors remains to be battery life. In numerous instances, supplying wired power can negate the cost savings linked to the wireless data aspect. Hence, there is a crucial need to extend the lifespan of these sensors. While both battery and low-power electronics technology have made significant strides over the last decade, another area of study that is increasingly feasible each year is wireless power. In the context of extremely low power electronics, wireless power transmission emerges as a viable and highly significant area of focus for both IoT and low-power electronics. The efficacy of wireless power relies on two crucial factors: the quantity of transmitted energy and the receiver's ability to efficiently utilize it. In the case of IoT sensors, the transmission distance typically spans from 2 to 10 meters. However, the necessary power for continuous operation is in the milliwatt range, and low duty cycles have the potential to decrease this to microwatts. In a commercial building setting, the current network infrastructure might have been extended to ports in the plenum space for Wireless Access Points (WAPs) and ports at floor level for computers. However, in the case of an environmental IoT sensor, accurate temperature measurement requires placement at human height in the room. An economical solution would be a wireless sensor with a patch antenna directly printed on the PCB, providing a cost-effective option to integrate sensors into rooms of a building that already has wireless infrastructure near the desired sensor placement.