A hand includes: a hand body; a first finger disposed to the hand body; a second finger disposed to the hand body; and an advance/retract actuator that advances and retracts the first finger in predetermined first directions relative to the hand body independently of the second finger. The first finger includes a belt defining a contact surface to contact an article and movable in in-plane directions of the contact surface.

A hand 100 includes a hand body 2, a gripper 3 that grips a workpiece, a coupler 4 that couples the gripper 3 to the hand body 2 such that a relative position of the gripper 3 to the hand body 2 is changeable, and a lock 9 that locks movement of the coupler 4. The lock 9 switches, by an opening/closing action, between a locked state where the lock 9 locks movement of the coupler 4 by contacting the gripper 3 and an unlocked state where the lock 9 unlocks movement of the coupler 4 by separating from the gripper 3.

A gripper, a manipulator, and an experimental device are provided. The gripper includes a fixed seat, a transmission rod, a movable seat, multiple transmission structures, and multiple fingers. The transmission rod is movably connected to the fixed seat. The movable seat is connected to the transmission rod and movable relative to the fixed seat in an axial direction of the transmission rod. The multiple transmission structures are movably connected to both the fixed seat and the movable seat. The multiple transmission structures are arranged at intervals in a circumferential direction of the transmission rod. The multiple fingers are connected to the multiple transmission structures in a one-to-one correspondence. The multiple transmission structures are configured to drive the multiple fingers to move synchronously in a radial direction of the transmission rod under the sequential drive of the transmission rod and the movable seat.