A startup makes IoT sensors, no batteries necessary

A startup founded by two MIT grads says that it can deploy self-powering sensors to handle low-intensity IoT tasks, eliminating the need for batteries or wired electrical supplies, adding a new level of flexibility to IoT deployments.

Ben Calhoun and Dave Wentzloff are the founders of Everactive, an IoT-device manufacturing startup whose sensor modules can create their own power from a variety of sources, including indoor solar, thermal gradient differential, and vibrations. The sensors can monitor for temperature, humidity, light levels, vibration, movement, sound, pressure and gas, among other things.

In addition to attacking the power problem from the supply side, the company addresses the demand side by minimizing the amount of power the sensors need through the use of sub-microwatt wakeup receivers for their radios and ultra-low-power integrated circuits.

The devices use thermal-gradient power – the use of waste heat generated, for example in, factories,– and indoor solar power – gathering energy from indoor lighting – to generate electricity. Neither technique generates much power, but they don’t need to for Everactive’s sensors.

Both thermal-gradient power and indoor solar are relatively well-understood technologies, but combining them with devices that have very low power requirements is what allows the company to provide self-powered IoT-sensors.

Everactive bills itself as a full-stack solution, sending data from the sensors to an on-premises gateway that can handle hundreds of sensors at a time, the company says.  The broadcast range of a sensor is 800 feet suing a proprietary wireless protocol that’s slimmed down to by eliminating some transmission steps that sap power. The protocol operates on a sub-GigaHertz frequency that propagates well through walls and other objects. The gateway connects to Everactive’s Evercloud back-end for monitoring and analysis. Everactive sells its offering as a service, charging around $25 a month per monitored device.

The real value of self-powered IoT sensors, the company says, is mostly in operational savings. A deployment of several thousand battery-powered sensors, even with lifespans of several years at a time, represents significant ongoing costs of replacing. Moreover, it makes certain IoT use cases much more practicable than they might otherwise be. Changing the batteries in a sensor monitoring activity at the rim of a volcano, for example, could be dangerous, and a self-powering sensor could be a boon to IoT users whose sensors are in similarly remote or dangerous locations.

The company’s showpiece product so far is a system to monitor steam-traps, automated valves that designed vent waste products from a steam system without losing any live steam. The autonomous sensors track temperature and moisture levels to spot potential problems as they arise and don’t have to worry about swapping out batteries. Other use cases, including remote-asset monitoring, are under development.