Introduction to Biomimetics: The Wealth of Inventions in Nature as an Inspiration for Human Innovation - Biomimetics: Biologically Inspired Technologies - page 22

Figure 1.15 A group of swallows gathering next to two nests that are made of a composite mix of mud and
straws. These nests were built under the author's roof (July 2004).

(a) bioluminescence — a voluntary or involuntary light emission, which results from a chemical

reaction;

(b) fluorescence — emission of light under ultraviolet illumination.

Bioluminescence can be found in various beetles (e.g., firefly), marine creatures (e.g., Pyrocystis
lunula , Gonyaulax polyedra , and squids), as well as certain bacteria, and mushrooms. Biolumin-
escence materials are used to attract females as in the case of the American firefly (Lloyd, 1984).
The male firefly flashes its light in order to ''declare'' its presence and identity, and to attract
females of its own species (Lloyd, 1966). Another example for bioluminescence is the glow-worm,
a type of beetle ( Noctiluca ), whose wingless female glows in the dark. Bioluminescence is also used
as a deception method, where the Photuris females mimic the flashing rate of hetero-specific males
and eat them (Lloyd, 1980).

1.6.5 Impact Sensitive Paint Mimicking Bruised Skin

Our skin is sensitive to impact leading to purple color marks in areas of the skin that is hit. This
bruise mark indicates the fact that the specific area has suffered an impact. This idea inspired
researchers at the South West Research Institute in the mid-1980s (Light et al., 1988) to develop a
surface coating as a nondestructive indicator of impact damage in composite materials. The need
for such an indicator rose as the use of composite material increased to a level where structures that
are critical to the safety of aircraft started to be introduced into military and commercial aircraft.