They can be used to drive a robotic arm, and they can even self-sense their position.

它们可以用来驱动机械臂，甚至可以自我感知自己的位置。

Scarlett blew her nose on her torn handkerchief, and they started up the dark drive arm in arm, the horse following slowly.

" 思嘉用她的奇手绢擤了擤鼻涕，然后他们彼此挽着胳臂走上黑暗的车道，那骑马在后面缓缓地跟着。