Reversibly expandable energy absorbing assembly and methods for operating the same

An interior vehicle surface, comprising:

• an energy absorbing assembly comprising a rigid support structure having an inlet opening;
• a flexible covering engaged with the rigid support structure to define an expandable interior region;
• a fluid source in fluid communication with the inlet opening;
• and a cellular lattice disposed in the expandable interior region, wherein the cellular lattice comprises a shape memory material adapted to expand from a first configuration to an expanded configuration in response to the fluid communication with the fluid source.

A method of operating an energy absorbing assembly, comprising:

• attaching the energy absorbing assembly to a rigid support structure having at least one inlet opening, wherein the energy absorbing assembly comprises a flexible covering engaged with the rigid support structure to define an expandable interior region, a fluid source in fluid communication with the inlet opening, and a cellular lattice disposed in the expandable interior region, wherein the cellular lattice consists of a shape memory material adapted to expand from a first configuration to an expanded configuration in response to the fluid communication with the fluid source;
• expanding the interior region including the cellular lattice from the first configuration to the expanded configuration with the fluid source at a temperature less than a transition temperature of the shape memory material;
• and
• thermally activating the shape memory material above the transition temperature causing the cellular lattice to revert back to the first configuration.