Pneumatically controlled lattices with tunable mechanical behavior.

Buckling is a common failure mode in lattice structures, limiting their use in some applications. The tendency of a strut to buckle is related to the local nodal connectivity. In this work, we introduce a pneumatic actuation strategy to actively tune the mechanical behavior of lattice structures by locally reconfiguring their effective nodal connectivity. By selectively inflating pneumatic actuators embedded in the lattice into spatial patterns with varying levels of connectivity, we demonstrate a method to modulate mechanical properties, including stiffness and buckling response. The most reinforced pattern can lead to 121.6% improvement in buckling strength relative to the regular lattice itself. Additionally, the post-buckling behavior of pneumatically controlled lattices can be programmably tuned by varying the input air pressure signals. The pneumatically controlled lattices reduced the peak acceleration by 50.9%, demonstrating enhanced impact mitigation capability. These results show that pneumatic actuation provides a versatile approach to enhancing structural performance under both static and dynamic loading. Since this strategy does not rely on multi-material interfaces or specific cell topologies, it can be broadly applied to optimize a wide range of lattice architectures.