Biomedical Engineering Reference
In-Depth Information
Chapter 9
Diversified Material Designs in Biological
Underwater Adhesives
Kei Kamino
9.1
Introduction
In nature there exists a variety of diversified adhesives to meet the individual
demands of many organisms. These adhesives have been artificially designed for
use in medicine, yet are fragile in water and thus are limited to air. Because
adhesive mechanisms that allow attachment under water are much more complex
than those that allow attachment in the air, we continue to study them, particularly
to characterize the adhesive's native proteins. In this chapter, we compare
biological material designs for similarities and differences from the macroscopic
to molecular levels to potentially provide clues for designing new artificial
adhesives. Specifically, we present information about how the mussel, barnacle,
and tubeworm inform us about how underwater “firm” adhesives work.
Many organisms prefer to attach to various interfaces such as gas-solid or
liquid-solid, since these attachments enable them to inhabit a fixed environment.
These attachments can actually become a part of the organism's physiological
function, and specialized processes have evolutionally developed to accomplish
this. An attachment could occur under water or in the air, with fixation or locomo-
tion, with the animal's body part attached to foreign materials or by joining
different foreign materials together. There may be differences in the attachment
area's size and surface cleanness, different time lengths needed to attain a full
strength of attachment, and differences of foreign stresses in the strength and
direction (tensile or shear) to be loaded.
Adhesives have been developed for commercial use in product manufacturing,
thanks to the assiduous efforts and experiences of material scientists and engineers.
However, their use in general remains limited to air, since attaching materials in
water remains a troublesome and undeveloped technology.
K. Kamino (
*
)
Biotechnology Center, National Institute of Technology and Evaluation, Kisarazu, Chiba, Japan
e-mail:
kamino-kei@nite.go.jp
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