Literature Review Part (C): Bioinspiration

Hi all! Today, we will share some bio-inspirations of starfish!  

Ossicals: resist fractures via microscopic holes in the structure

'Foamy' materials in which any threatening crack will be in short order run into a hole. This reduces the chance of cracking. The little hard bits of echinoderms, the ossicles, develop as single crystals, but they avoid excessive brittleness of typical crystals by being especially holey.

Bioinspired products/applications: 

Construction, ceramics, material science, building science, pipes

·        Concrete & building materials for construction, 

·        Packaging materials (save more energy during recycling),

·        Plastics e.g. computer case (prevent cracks from spreading),

·        Pipes ('self-arrest' any cracks)

Source: 1) Vogel S. 2003. Comparative Biomechanics: Life's Physical World. Princeton: Princeton University Press. 580 p.

Tube feet: move & handle food using hydraulic system

Something similar happens in echinoderm tube feet-small, soft, unjointed and exceedingly numerous organs used for locomotion and handling food which are noticeable when a starfish creeps up the glass wall of an aquarium. Ampilla, which available above each tube foot is a bulbous chamber that is equipped with circular muscles and reinforcing fibers at right angle to that muscle. The contraction of foot muscle forces the expelled fluid into the ampulla by extending its muscle. That couples the food muscle and ampulla in a hydraulically linked antagonism (McCurley and Kier 1995). The whole thing hooks onto the water-vascular system of pipes to vary the overall volume. A one-way flap valve prevents contraction of either foot or ampullary muscle from forcing water back into the pipes at the same time (Maerkel and Roesel 1992).

Bioinspired products/applications:

Safety mechanisms for pipes, water supply & sanitation, oil and gas

Source: 1) Vogel S. 2003. Comparative Biomechanics: Life's Physical World. Princeton: Princeton University Press. 580 p.

2) McCurley, RS; Kier, WM. 1995. The functional biology of starfish tube feet: the role of a crossed-fiber helical array in movement. The Biological Bulletin. 188(2): 197-209

3) Maerkel, K; Roeser, U. 1992. Functional anatomy of the valves in the ambulacral system of sea urchins (Echinodermata: Echinoidea). Zoomorphology. 111: 179-192.

Body: helps buffer thermal variations in low tide by taking up and storing cold sea water during high tide

Scientists have discovered that starfish has remarkable strategy to avoid overheating in the sun. It pumps itself up with cold seawater to lower the body temperature when being exposed to the sun at low tide. It is equivalent to a person drinking 7 L of water before heading into the midday sun (Bourton 2009). The body temperature of ectotherms is influenced by the interaction of abiotic conditions, morphology and behaviour. Organisms living in different thermal habitats may exhibit morphological plasticity or move from unfavourable locations. 

When starfish exposed to high body temperature at low tide, it increases the amount of colder-than-air fluid in their coelomic cavity when submerged during high tide, resulting in a lower body temperature during the subsequent high tide. The enables them to modify the coelomic fluid volume which provides them with a novel thermoregulatory 'backup' during prolonged exposure to elevated aerial temperatures (Pincebourde et al. 2009).

Bioinspired products/applications:

Electronics, Computer science, Building, Construction, Manufacturing

·        Buffer temperature fluctuations in buildings

·        Computer equipment by adding a fluid

     
Source: 1) BourtonJ. 2009. Starfish 'pump up' to cool down. BBC Earth News

2) Pincebourde S; Sanford E; Helmult B. 2009. An intertidal sea star adjusts thermal inertia to avoid extreme body temperatures. American Naturalist. 174(6): 890-7.

Legs & tubes: allow movement and feeding by hydrostatic pressure

The echinoderms bodies work by unique exploitation of hydrostatic principles. Each thin tube of the feet ending in a sucker is being kept firm by the pressure of water within the waves and curl in rows along the arms. When a drifting particle of food touches an arm, tube feet fasten onto it and pass it on from one to another until it reaches the gutter that runs down the upper surface of the arm to the mouth at the centre (Attenborough 1979:49).

Bioinspired products/applications:

Prosthetic limbs, robotics, transportation or other movement using water pressure, manufacturing, medical, transportation industries

Source: 1) Attenborough, David. 1979. Life on Earth. Boston, MA: Little, Brown and Company. 319 p.

Arms: self-repair / self-healing

Self-healing solves the quality assurance problem and reduces life cycle costs. The extended life reduces the number of replacements as well as future costs. This self-repairing materials is less expensive because the repair material is built in and high availability. 

Bioinspired products/applications:

Self-repairing concrete 

·        consists of repair material in hollow fibers in the repair matrix before it is subjected to damage; the usual approaches for structural concrete repair are polymer injection, pre-stressing, geomembranes and polymer wraps where these techniques are ductile, less brittle failure and unstable.

Polymer composites

·        With unique toughness and strength by self-repair which occurs at material interfaces and damaged areas. It is repaired by releasing repair chemicals from within the composites itself. The hollow fibers are embedded in the matrix and the chemicals are released whenever there is cracking or other matrix damage occurs. The crack faces are rebounded when the repair chemical flows into the crack.

Source: 1) The Natural Process Design, Inc. 

That's all for today! Till next time! =)