Control of nanoenergetics through organized microstructures

Heavily doped p-type silicon substrates were etched to form thick porous layers (170 m) and impregnated with magnesium perchlorate to form reactive composites. Characterization of the reactive wave propagation by high speed photography and spectroscopic methods indicated slow propagation rates between 1 and 8 m s ¹. Multiscale structures were formed on the same substrates using microfabrication techniques followed by an electrochemical etch based on a random micro-crack pattern observed in lower doped substrates which yielded faster propagating composites. These organized multiscale composites exhibited flame propagation speeds up to 500 m s ¹indicating that reaction propagation can be controlled by structural modifications.