Demo Abstract: A Long-Lifetime Sensor Platform for a Reliable Internet of Things

Today, most energy harvesting sensors rely on capacitors to buffer small amounts of energy as they intermittently work through a sensing task. While the utilization of capacitors for energy storage affords these systems indefinite lifetimes, their low energy capacity necessitates complex intermittent programming models for state retention and energy management. Recent advances in battery technology lead us to reevaluate the impact that increased energy storage capacity may have on the necessity of these programming models and the reliability and lifetime of energy harvesting sensors. Permamote, presented at IPSN 2019, is designed to explore the benefits of larger capacity energy harvesting Instead of a capacitor, Permamote utilizes a small lithium battery to store harvested energy. The inclusion and size of this battery was determined based on device reliability and lifetime modelling using real indoor solar irradiance traces. Permamote additionally includes a backup, non-rechargeable battery that allows continuous operation even for long periods of no available harvestable energy. In this demo, we present Permamote performing continuous and reliable sensing over a Thread (6LoWPAN 802.15.4) mesh network. Additionally, we show the end-to-end cloud infrastructure supporting connected Permamotes, with the intention of showing that energy harvesting with higher capacity enables more capable sensing.