Comments on: Sensors: Living off scraps of energy

In the future, your shoes may be able to charge your camera and RFID chips could tell when you leave the room.
Images: Energy-saving sensors

[cryforlife]

Highly Misleading

These are NOT perpetual motion devices. The writer says so himself... so why on earth the misleading headline?

[baswwe]

Message has been deleted.

[baswwe]

He's preparing to write for those Tabloid newspapers!

nm

[ewelch]

Doesn't know what they are

Some people don't know what perpetual motion machines would be
if they could exist - which they can't.

:-D

[Jon Skillings]

Headline changed

The writer does make this point as well, referring to perpetual motion: But from a practical point of view, these devices come close to that ideal because they can survive on energy that otherwise would be unused and they get it on their own.

And the headline was a question, not a statement.

But your larger point is well taken. We've changed the headline to fit the story's focus on sensors and their energy consumption.

[DeusExMachina]

Because?

It is CNet

[Seaspray0]

Devices like that already in use

Many cigarette lighters no longer use a flint, but have a piezoelectric crystal imbedded in them to generate the spark that lights the flame. One watch maker created a watch that runs on a photovoltaic (also doubles as the faceplate). It stored the charge for when you were indoors or at night. I've also seen a mechanical watch that used the movement on your wrist to rewind itself. The warning lights on the school zone signs in my neighborhood are powered by solar cells which stores the charge in batteries.