Bio-inspired Engineering

HW-1

Submitted byArunkumar Rengaraj

Submitted ToProf. Kwon

1. What is the mechanism of controlled adhesion by wet adhesion that is based on capillary interaction?

• The fact that a fly can walk on a vertical glass window is due to capillary bridges formed at the tip of many thin hair-like fibers, which cover the attachment organs of the

fly; Figure 1.

• When two elastic solids with rough surfaces are squeezed together, the solids will in general not make contact everywhere in the apparent contact area, but only at a

distribution of asperity contact spots (Those act like capillary) Figure 2

Figure 1 Figure 2

2. What is the mechanism of controlled adhesion by dry adhesion using van der Waals forces.

• The toes of live Tokay geckos were highly hydrophobic, and adhered equally well to strongly hydrophobic and strongly hydrophilic, polarizable surfaces

• A van der Waals mechanism implies that the remarkable adhesive properties of gecko setae are merely a result of the size and shape of the tips, and are not

strongly affected by surface chemistry

What is the mechanism of controlled adhesion of Octopus and Leech?

• Octopuses use suckers to anchor the body to the substrate or to grasp

• observe some morphological differences with respect to the octopus species previously studied (i.e., Octopus joubini, Octopus maya, Octopus bimaculoides/bimaculatus and

Eledone cirrosa).

• In particular, in O. vulgaris the acetabular chamber, that is a hollow spherical cavity in other octopuses, shows an ellipsoidal cavity which roof has an important protuberance

with surface roughness.

• We hypothesize that the process of continuous adhesion is achieved by sealing the orifice between acetabulum and infundibulum portions via the acetabular protuberance

What do you want to apply the above mechanisms to?

I want to develop biomimetic material ,which having surface property to attach with the different type of surface

So I can use this material for different application