Suction Cup

What is a suction cup?

A suction cup is basically a device that adheres onto a surface for various applications. Some of the various applications of suction cups are:
1)To adhere objects onto tile walls
2)To move glass panes
3)Nerf darts
4)Toilet plungers

Problem of a suction cup:

Currently, suction cups that are available in the market can only adhere to flat, clean and dry surfaces. When suction cups are applied onto wet/slimy/ rough surfaces the suction power is almost insignificant. Suction cups depends on the pressure difference inside the suction cup and the atmospheric pressure. When suction cups are pressed, the volume of air inside the cup reduces, thus reducing pressure. The higher atmospheric pressure pushes the cup inwards, causing them to adhere to surfaces. On rough surface, the surface is uneven and there is air leakages causing the pressure to be insufficient for proper suction power.

Figure 1. Suction on uneven surface

Possible solution inspired by Pleco:

Figure 2. Microvilli producing friction on uneven surfaces

Pleco is able to adhere to various surfaces as they have microscopic ‘hair’ or microvilli on their specific suction region. These flexible microvilli produces friction onto uneven surfaces providing more grip onto the surfaces. In addition, these microvilli blocks the leaking air pathway which produces the pressure difference more efficiently. Thus, this enables the Pleco to attach onto various surfaces.