Articles
But today, in the age of simulation and artificial intelligence, how much more can nature teach us?
Some call their work biomimicry, while others prefer the term bio-inspired engineering. Regardless of labels, this week we are looking at five projects and their biological inspirations, revealing how nature continues to offer engineers a guiding hand.
Solar cells
While engineers look to all things bright and beautiful – and slime – for inspiration, nature itself faces an existential threat. Human-caused climate change is damaging habitats and ravaging populations. Engineers are turning back to nature for solutions.
A team from the Karlsruhe Institute of Technology in Germany took inspiration from the common rose butterfly, Pachliopta aristolochiae, in an attempt to improve solar cell sunlight absorption and help reduce over-reliance on fossil fuels.
Thin-film photovoltaic modules are an economically attractive alternative to conventional crystalline silicon solar cells, as their light-absorbing layers are up to 1,000 times thinner and therefore require much less material. Absorption rates are below crystalline silicon, however, meaning they are mostly used for low-power systems.
The black of the butterfly’s wings is very dark, telling the researchers they manage heat by absorbing high levels of light – something of huge importance for solar energy. Using an electron microscope, the team found that the wings are drilled through with disorderly tiny holes with varying diameters known as nanoholes.
The researchers added nanoholes of 133-343nm to their thin-film solar absorber, made of hydrogenated amorphous silicon, at disorderly intervals. Compared to smooth surfaces, the absorption rate of perpendicular light increased by 97%, and continued to rise up to an angle of incidence of 50°.
The researchers claimed the technique could be suitable for thin films of other materials, but admitted that a 200% efficiency increase over standard surfaces is a theoretical limit. Nonetheless, perhaps it is the kind of ambition needed to tackle the seemingly insurmountable challenge that climate change poses. And where better to look for inspiration than nature itself?
Read part one of Nature's Blueprint, on the dragonfly-inspired Skeeter drone, here.
Read part two, on the sea snake-styled Eelume, here.
Read part three, on the budgie-influenced Quad-Morphing drone, here.
Read part four, on how slime mould could inspire self-driving car development, here.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.