Produce what you consume!

The Internet of Things is the imagined network of data links that will emerge when everyday objects are fitted with tiny identifying devices. The idea is that every parcel in a post office would transmit its position, origin and destination so that it can be tracked and routed more efficiently, that every product on a supermarket shelf would transmit its contents, price, shelf life and so on, that your smartphone would interrogate the contents of your fridge and cupboards every time you walk into the kitchen to warn you when the milk is running low. And so on.

Each of these things will enhance our businesses and lifestyles in a small way. But there’s a problem: these tiny identifying devices require a power source. Batteries are expensive and impractical so computer scientists are hoping to harvest the necessary energy from the environment, in particular from lights and from human motion.

Maria Gorlatova and pals at Columbia University in New York measured the inertial energy available from the activity of 40 individuals over periods up to 9 days. To do this they attached to each person inertial energy harvesting devices, essentially a mass attached a spring, that recorded their motion.

They also measured the power available from the movement of objects such as doors, drawers and pencils to see how much might be harvested here.

Here’s a list of their main findings: Periodic motion is energy rich. So writing with a pencil generates more power (10-15 microwatts) than the acceleration associated with a 3-hour flight flight including take off! Humans are passive most of the time. About 95 per cent of the total harvestable energy they produce is generated during less than 7 per cent of the day. Most people generate enough power to continuously transmit data at the rate of about 1 Kb/s (more than 5 microwatts). Why not tap all that wasted energy for little applications?