In this work, a systematic experimental study of the rupture of an axially symmetric liquid bridge between a cone and a plane was performed, with focus on the volume distribution after break up. A model based on the Young-Laplace equation is presented and its solutions are compared to experimental data. Cones and conical cavities with different aperture angles were used in our experiments. We found that this aperture influences the potential pinning of the contact line, the meniscus shape and therefore the liquid transfer. For half aperture angles α < 70°, where no pinning was observed, the liquid bridge slips off from the cone and almost no transfer to the cone is observed. However, at α > 70°, contact line pinning on the cone induces a net liquid transfer to the cone at rupture. In the case of conical cavities, a maximum of liquid transfer is observed for at α =110°. The distance at which the rupture of the liquid bridge occurs is also discussed. The model can fairly predict the transfer ratio and the rupture height of the liquid bridge.

We propose a new 3D-printed capillary gripper equipped with a textured surface for motion-free release of micro-objects. The release process can be controlled by IR laser. We also discuss the minimal conditions for release.