Inspired by the way plants grow, MIT researchers designed a flexible robot appendage that can work in tight spaces but is rigid enough to support heavy parts or twist tight screws. From MIT News:
The appendage design is inspired by the way plants grow, which involves the transport of nutrients, in a fluidized form, up to the plant's tip. There, they are converted into solid material to produce, bit by bit, a supportive stem.
Likewise, the robot consists of a "growing point," or gearbox, that pulls a loose chain of interlocking blocks into the box. Gears in the box then lock the chain units together and feed the chain out, unit by unit, as a rigid appendage…
"The realization of the robot is totally different from a real plant, but it exhibits the same kind of functionality, at a certain abstract level," (mechanical engineer Harry) Asada says.