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32 Biomimetics: Biologically Inspired Technologies

potential sponsors and users, and lead to general public awareness since it is hoped that they will be
the end users and beneficiaries in many areas including medical, commercial, and military. The first
arm-wrestling competition with humans was held against a 17-year-old girl on March 7, 2005 and
the girl won against three robotic arms that participated. Even though the arms did not beat the
challenge, one of the arms was able to hold against the girl for 26 sec, and this is an important
milestone.

1.8.2 Aerodynamic and Hydrodynamic Mobility

Judging from the number of flying insects, birds, and marine creatures, nature has ‘‘experimented’’
extensively with aerodynamics and hydrodynamics. There are several aspects that deserve atten-
tion. For instance, birds can catch fish underwater with their eyes closed. They are able to catch fish
by taking into account the refraction-effect, which creates an illusion as to the location of the fish.
Birds and various mammal predators take into account the vector trajectory of the escaping prey, as
in the case of hunting a running rabbit or deer. These trajectories are increasingly the capability of
military weapons allowing tanks to destroy a moving target while they are moving too. Sophisti-
cated capabilities are used to track the moving target and either adjust the direction in flight or aim
upon launch using high speed missiles or bullets.
The ability of the dragonfly to maneuver at high speed is another aspect of flying that
considerably inspired humans. Using a liquid-filled sac that surrounds its cardiac system, the
dragonfly adjusts the effects of high G on its body during its flight and incredible maneuvers.
G represents unit of gravitational force on Earth where high G is many multiples of one G. This
technique inspired a mechanism that allows pilots to fly at high mach speed with significantly lower
effects on the ability of the pilot to stay coherent. A liquid-filled, anti-G suit was developed by Life
Support Systems, a Swiss company, and the suit is called ‘‘Libelle,’’ which means in German
‘‘dragonfly’’ (http://www.airpower.at/news01/0625_libelle/libelle3.htm). The Libelle suit promises
advantages over the pneumatic (compressed air) anti-G suits that are currently in use at various air
forces including the US Air Force. Instead of air, Libelle uses water to provide counter pressure
proportional to the gravitation force. The fluid is contained in expandable, snake-like tubes that run
from the neck to the ankles and over the shoulders to the wrists (http://www.txkell.ang.af.mil/news_
events/suit.htm).
Like biology, botany also takes aerodynamics into account. The seeds of many plants
are designed with features that allow them to disperse away from their origin. The need to
disperse can be attributed to the possibility of overcrowding of the specific type of plant in the
same local area. Seeds use various aerodynamic techniques to be propelled by the aid of winds,
for example, see Figure 1.20 the winged seed of the Tipuana tipu (about 6.5-cm long). Such seeds
have inspired designs of futuristic missions with spacecraft that would soft-land on planets with
atmospheres such as Mars. Adapting this design may allow for designing a parachute with better

Figure 1.20 Seeds of the Tipuana tipu, which has an aerodynamic shape for dispersion by wind.