Making and breaking contacts between metal particles

When you plug in your toaster, you expect metallic contacts to form and carry electricity. You can safely ignore the many microscopic contacts that form and break when you unplug it. We cannot ignore them when designing stretchable conductors, sensors, or batteries containing conductive particles in insulating matrices. I will show how we used FIB-SEM tomography to reconstruct the networks formed by conductive filler particles in conductive polymer composites (CPCs). The results show that the macroscopic conductivity of these materials is strongly influenced by local contact resistances. These contacts can be tuned: we made CPCs with carbon platelets as conductive components for soft-robotics applications and found that aligning them considerably changes the local contact geometry, bulk co