Abstract: Techniques for controlling grasping include a manipulator configured to be releasably coupled to an instrument, the instrument having an end effector comprising a first jaw and a second jaw; a drive system configured to apply a force or torque to the instrument to cause the end effector to grasp a material between the first jaw and the second jaw; and a processor. The processor is configured to monitor a force or torque applied by the drive system to cause the end effector to grasp the material and in response to a determination that the applied force or torque is below a lower limit of an acceptable range of force or torque, reverse a direction of the applied force or torque.