IDLab-Faculty of Applied Engineering, University of Antwerp-imec, Sint-Pietersvliet 7, 2000 Antwerp, Belgium.
Sensors (Basel). 2022 Jun 23;22(13):4737. doi: 10.3390/s22134737.
Energy harvesting is an effective technique for prolonging the lifetime of Internet of Things devices and Wireless Sensor Networks. In applications such as environmental sensing, which demands a deploy-and-forget architecture, energy harvesting is an unavoidable technology. Thermal energy is one of the most widely used sources for energy harvesting. A thermal energy harvester can convert a thermal gradient into electrical energy. Thus, the temperature difference between the soil and air could act as a vital source of energy for an environmental sensing device. In this paper, we present a proof-of-concept design of an environmental sensing node that harvests energy from soil temperature and uses the DASH7 communication protocol for connectivity. We evaluate the soil temperature and air temperature based on the data collected from two locations: one in Belgium and the other in Iceland. Using these datasets, we calculate the amount of energy that is producible from both of these sites. We further design power management and monitoring circuit and use a supercapacitor as the energy storage element, hence making it battery-less. Finally, we deploy the proof-of-concept prototype in the field and evaluate its performance. We demonstrate that the system can harvest, on average, 178.74 mJ and is enough to perform at least 5 DASH7 transmissions and 100 sensing tasks per day.
能量收集是延长物联网设备和无线传感器网络寿命的有效技术。在环境传感等应用中，需要采用即插即用的架构，能量收集是一种不可避免的技术。热能是能量收集最广泛使用的来源之一。热能收集器可以将温度梯度转化为电能。因此，土壤和空气之间的温差可以成为环境传感设备的重要能源。在本文中，我们提出了一种从土壤温度中收集能量的环境传感节点的概念验证设计，并使用 DASH7 通信协议进行连接。我们根据从两个地点收集的数据评估土壤温度和空气温度：一个在比利时，另一个在冰岛。使用这些数据集，我们计算了这两个地点产生的能量。我们进一步设计了电源管理和监控电路，并使用超级电容器作为储能元件，因此使其无电池。最后，我们在现场部署了概念验证原型并评估了其性能。我们证明该系统平均可收集 178.74 毫焦耳的能量，足以每天执行至少 5 次 DASH7 传输和 100 次传感任务。
