Smart microchip keeps going when batteries run dry – Futurity
One of the key challenges of moving Internet of Things (IoT) devices from concept to reality is the need for long-lasting operation under tightly constrained energy sources, which demands extreme power efficiency. IoT devices—such as sensors—are often deployed on a massive scale and in places that are usually remote and difficult to service regularly, thus making their self-sufficiency essential.
Currently, batteries in IoT devices are much larger and up to three times more expensive than the single chip they power. Their size is determined by the sensor node lifetime, which directly affects how often they need changing. This has an important bearing on maintenance cost and impact on the environment when people dispose these batteries.
To extend the overall lifetime, the batteries usually recharge slowly by harvesting some limited power from the environment, such as using a solar cell. However, existing IoT devices cannot operate without batteries, and small batteries are fully discharged more frequently. Hence, battery miniaturization often results in highly discontinuous operation of IoT devices, as they stop functioning every time the battery runs out of energy.