Energy-Efficient System Architectures for Intermittently-Powered IoT Devices

Various industry forecasts project that, by 2020, there will be around 50 billion devices connected to the Internet of Things (IoT), helping to engineer new solutions to societal-scale problems such as healthcare, energy conservation, transportation, etc. Most of these devices will be wireless due to the expense, inconvenience, or in some cases, the sheer infeasibility of wiring them. With no cord for power and limited space for a battery, powering these devices for operating in a set-and-forget mode (i.e., achieve several months to possibly years of unattended operation) becomes a daunting challenge. Environmental energy harvesting (where the system powers itself using energy that it scavenges from its operating environment) has been shown to be a promising and viable option for powering these IoT devices. However, ambient energy sources (such as vibration, wind, RF signals) are often minuscule, unreliable, and intermittent in nature, which can lead to frequent intervals of power loss. Performing computations reliably in the face of such power supply interruptions is challenging

Demonstration of a Platform Architecture That Enables Ultra-Low Power IoT Applications

The coming years will see a surge of billions more devices connected in an “Internet of Things” (IoT) that aim to improve the day to day life of humans by sensing relevant physical phenomena and using the data to make intelligent decisions and predictions. But with current devices, this surge will result in billions more batteries needing to be used and changed regularly. The need for batteries—and its impact—can be mitigated through low power devices that harvest ambient energy (e.g. solar, vibrational, thermoelectric, radio wave), but energy harvesting devices require the ability to continue computations across power cycles, a paradigm known as transiently powered computing. The Embedded Systems Lab has designed the QUBE embedded hardware platform to meet this need. The QUBE’s capabilities have been demonstrated in the lab, but the QUBE has never been used in a real world application. The QUBE is paired to a smartphone via Bluetooth and data received from its environmental sensors is transmitted in real-time. Power is turned on and off to simulate power cycling