Bits and Bobs - Solar-Powered Hornets
Looking for some ‘green’ technology to cut your energy bills? Maybe you should check out the Oriental hornet. Unlike many other wasp species, the Oriental hornet (Vespa orientalis) becomes most active in the heat of the afternoon. In fact, the industrious insect digs its nest most intensely when exposed to the most extreme rays from the sun. This odd behaviour caught the attention of researchers at Tel Aviv University in Israel.
Using atomic force microscopy (which provides three-dimensional images down to an atomic scale), the team zoomed in on the brown and yellow stripes on the hornet’s abdomen. Although the surface, or cuticle, appears smooth, it actually contains layers and layers of microstructures that appear to ‘harvest parts of the solar radiation’. In other words, the hornet may be a flying solar panel.
Up close, the brown stripes reveal a ridge-like structure, somewhat similar to a terraced hill. As light rays pass through each layer, the structures split the light and trap extra energy for conversion into electric power. The yellow stripe also has many layers that trap light, although the structures are different.
The actual conversion to electricity is accomplished by the yellow pigment xanthopterin (which is also found in the wings of some butterflies). At this point, however, researchers are still investigating how the wasps use this harvested solar energy. We know that their active digging corresponds with increased absorption of the sun’s rays. But we don’t know whether this increased activity is simply a result of absorbing heat from the sun (as is common with many animals). Researchers suspect that something else lies beneath the surface. Does the electrical energy gained ‘charge up’ the wasp to do actual work (similar to how our bodies convert food into chemical energy, called ATP, which our cells use to do their work)? To test this idea, researchers placed this yellow chemical in a solar cell and found that it can indeed absorb sunlight and convert it into electric energy, similar to the silicon-based solar cells that humans have developed.
The researchers’ attempt to copy the solar prowess of the hornet lacked the same spark, but they hope to refine their models in the future, perhaps as an economical alternative to silicon cells. Yet another technological marvel with potential application to human technology is the hornet’s ability to remove all that extra heat. Like a modern refrigerator, this versatile vespine houses a sophisticated heat pump that keeps it from overheating! The researchers claim the hornet itself somehow ‘solved’ these design problems by evolving such complex and interdependent structures. Sadly, they remain in the dark about the One who cares for all His creatures — even those pesky hornets.