Today's word is . . . biomimetic!

The prefix "bio" tells you we're talking about living things, and "mimic" would imply imitation of something. Biomimetics is the study of technology that imitates living things.

For example, spider legs. Researchers who work on space machinery have taken inspiration for the robotic arms they build from spider legs. Vertebrates like us use muscles to bend our arms and legs, but arachnids, such as spiders, move their limbs by pumping fluid in and out of them.

In spiders, a fluid called hemolymph can be forced into the limbs, making them extend or contract. It's a simple hydraulic system that designers are trying to replicate for the arms of space probes.

The more joints you put on a limb, the greater range of flexibility it has. With mechanical sensors to tell how much fluid pressure there is at different points on the robotic arm, and an electronic feedback mechanism, you should be able to build a robot with multiple limbs capable of fairly sophisticated movement.