Tiny, flapping flags to generate wind power

WASHINGTON: Researchers have developed a generator that can harvest wind power from the friction of tiny, flapping flags.

The experimental generator builds a charge using mechanics that are similar to rubbing a balloon on someone's head.

When a breeze hits the small contraption, the electrode-coated flag stirs into motion, brushing against a conducting counter plate, 'Wired.com' reported.

This rubbing action develops a static charge on the counter plate's polymer surface, a process called the triboelectric effect. A small capacitor gathers the charge.

All the flags are small - less than 5 inches in length, and 4 in width - but vary in their dimensions. The researchers built them from a synthetic textile coated with gold, a highly efficient conductor.

Each counter plate sandwiched another piece of this gold-coated fabric between a stiff baseboard and a Teflon-like polymer called PTFE.

When the gold flag flaps against it, it builds up a nice static charge, which the gold in the baseboard then conducts into the capacitor, the report said.

The team developed several of the devices to test different length and width configurations. In a low breeze, longer, thinner flags generated more charge because they contacted the counter plate more often.

The research was published in the journal Nature Communications.