Retention of deformable memory material in flow path

A device comprising:

• a structure comprising fixed interior side walls defining a flow path;
• a memory material component disposed within the flow path;
• wherein the component is secured within the flow path by abutment against the side walls in response to:
• a deformation operation to transition the component from a rest state to a deformed state for insertion into the flow path, and
• an application of a stimulus to transition the component from the deformed state to an intermediate state in which the component abuts the side walls, wherein the component comprises a memory polymer configured to passively receive the stimulus from an external source to transition from the deformed state to the intermediate state;
• wherein the component comprises is a catalyst configured to facilitate a reaction in response to a precursor received through the flow path;
• wherein the structure is part of a chemical detector responsive to the reaction to determine whether a material of interest is present;
• and
• wherein the component in the rest state exhibits a first width greater than an interior diameter of the flow path, the component in the deformed state exhibits a second width smaller than the interior diameter, and the component in the intermediate state exhibits a third width between the first and second widths.