Final answer:
Vacuum suction cups are a suitable type of gripper for flat work pieces, but not for spherical or porous ones.
Step-by-step explanation:
When it comes to gripping flat work pieces, the most suitable grippers are vacuum suction cups. These grippers use negative pressure to hold the work piece in place. They work well with flat surfaces as the suction cup can create a seal and maintain grip. However, vacuum suction cups are not effective for gripping spherical or porous work pieces, as they cannot create a proper seal.
For example, if you are trying to pick up a flat metal sheet, a vacuum suction cup would be a good choice as it can create enough suction to firmly hold the sheet in place. On the other hand, if you are trying to grip a porous material like a sponge, a vacuum suction cup would not be suitable as air can easily pass through the pores, causing the grip to be weak or non-existent.
In conclusion, vacuum suction cups are especially suitable for flat work pieces, but not for spherical or porous ones.