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Abstract:
(Invited Talks)
The fabrication of material and structures inspired by nature,
an old-rooted endeavour of man, is again being actively pursued
under a renewed name: biomimesis. This approach, which once
belonged to the realm of biological sciences, is based on the
observation that when one tries to embody our recognition criteria
for biological organisms in an explicit list, nothing can be found
on that list that cannot be mimicked by some inorganic system.
Hence, a large variety of artefacts can be made, all possessing, to
some extent, life-like features. Biomimetic arguments are today
common in experimental studies on the origin-of-life, and in
advanced robotics; a relatively new area which has also started
making use of biomimetic reasoning pertains to materials science.
Sensory motor co-ordination and control are very basic and
essential features of biological organisms; According to classical
engineering criteria, biological mechanoreception and motility are
accomplished by embedded, redundant sensors and actuators combined
with local processors in purposely conceived monolithic structures.
This design philosophy is largely different from the one used
presently in engineering, which is based on precisely machined
mechanical parts and localised electromechanical sensors and
actuators, governed by silicon processors. Attempting to mimic both
muscular and neural aspects in an advanced robot has practical
relevance in a number of significant cases, particularly for those
applications in which conventional control techniques score poorly
with respect to human performance. This is the case, for example,
of handling natural objects in a natural environment. The basic
matter of which biological systems are made of is a sort of
jelly-like composite material swollen in a multicomponent aqueous
solution. From a mechanical stand point it is a poor material with
which it is impossible to design precise mechanisms. However, it is
efficient and versatile and can be used for transduction,
conduction, computation and actuation. There is increasing evidence
that mechanoreception, pseudo-muscular actuation and, even, analog
computation can be implemented using polyelectrolyte gels and
extrinsic polymeric conductors, which possess mechanical and
actuation properties very similar to living matter. For example,
tactile sensing by skin-analogs made of weakly ionised polymer gels
has been reported. Ionised polymer gels, extrinsic conducting
polymers and polycarbon phases have been analyzed in detail and
discussed in view of possible applications in pseudomuscular
actuation technology. Amplification, rectification, variable
resistance and chemoelectric transduction have all been
demonstrated in extrinsic conducting polymers, and they represent
essential features eventually leading to computational structures
based on hybrid ionic-electronic effects.
Danilo De Rossi graduated in Chemical Engineering from the
University of Genova in 1976. From 1976 to 1981 he has been
researcher of the Institute of Clinical Physiology of C.N.R., where
he presently coordinates the group for research on materials. He
has worked in France, USA, Brazil and Japan. Since 1982, he has
been working in the Faculty of Engineering of the University of
Pisa, where he is Professor of Bioengineering and director of the
Interdepartmental Research Center "E.Piaggio". His scientific
interests are related to the physics of organic and polymeric
materials, and to the design of sensors and actuators for
bioengineering and robotics. He received the "Bioengineering Forum
Award" of the Biological Engineering Society (UK) in 1980, and the
"Young Investigator Award" of the American Society for Artificial
Organs (USA) in 1985. He is author of over 150 technical and
scientific publications.
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