Piezoelectric Tree to Convert Wind Energy to Electric Power

Since entering the lexicon of green technology the term piezoelectricity seems to come up in almost every other article that we upload here. What we are about to tell you now is a technology that uses the concept of piezoelectricity to build an artificial tree that can harvest wind energy to produce electricity!

How?

Synthetic piezoelectric leaves are connected to a stem and these leaves flap in the wind like an oscillating flag. The device is then able to convert the energy in wind into electric power while remaining light, low-cost, and easily scaled.

More about this energy harvesting piezo-tree…

The flapping motion of the synthetic leaves is attributed to instability of the aero-elastic system. When creating this tree researchers have used the flexible piezoelectric material Polyvinylidene Fluoride (PVDF) as the basic component, as it could withstand unpredictable wind strength. An AC signal is collected from the flapping piezo-leaf, which works on a periodic bending model, and the electrical energy is then stored in a capacitor.

However…

Because of the weak ‘piezoelectric strain coefficient’ of PVDF, the power generated was just about 100 pW (pico watt), unable to light even a common LED.

So…

The researchers attached a piece of plastic film to the end of the leaf along the direction of air flow, which increased the amount of power generated by about 100 times! A series of experiments were also conducted using attachments of various shape, area, density and flexibility of plastic and polymer film to produce different results in the level of power.

So who are these researchers?

Scientists at Cornell University, New York, USA.

Why bother?

As a simple, robust, and easily scaled device, this ‘piezo-tree’ would serve as an effective and unique power generator in a variety of environments. For practical application the researchers hope to build plant-like devices with hundreds or thousands of piezo-leaves!

via: Cornell University