XPLOZ4D – 4D printed composites for passive explosive energy release

The separation of a launch vehicle’s fairing halves currently relies on pyrotechnic systems, which release the kinetic energy required for separation. These systems are triggered by a command signal transmitted through mechanical or electronic means. However, they are associated with high cost and mass, as well as significant safety risks and environmental impacts.

Multistable structures are increasingly being investigated for the rapid release of stored elastic energy through elastic instabilities, such as snap-through. Current actuation methods typically rely on magnetic stimulation, combustion, or explosives rather than passive mechanisms that operate without human intervention.

Building on biomimicry and 4D printing, the 4D XPLOZ project aims to draw inspiration from natural mechanisms to develop 4D composite metastructures capable of releasing programmed elastic energy rapidly. This capability will be governed by two key factors: (i) the controlled pre-strain introduced during manufacturing and (ii) the interactions between the structure’s architecture and environmental variations. Beyond space applications, these architected materials could also be used in soft robotics and integrated into deployment mechanisms for swarms of aerial or marine drones.