Offset teeth on each gripper interlock with those of its pair to better control sample acquisition. The geometry of the combined two grippers pushes the sample towards the tool's center as the grippers close. Due to the axially symmetric nature of this pattern, the same design can be used for both sides. This feature is aided by a function which wiggles the tool slightly along the X-Y plane before fully closing the grippers. Together, these features allow for the compliance necessary to be left unattended for multiple days.