Comment by nhma

The gripper has several modes. There's a mode for charging the battery and providing holding force given AC powerline current, a mode for just holding the drone without charging given AC powerline current (if battery is full), and another mode where a small current (about 1W power) is taken from the battery and used to provide holding force in the case where there is no powerline current. Additionally, the gripper can be designed to fail open or fail closed, whichever is deemed appriate for the end-user.