Using microfluidic technology to prepare octogen high-energy microspheres containing copper–aluminum composite particles with enhanced combustion performance

•Microfluidics can be used to prepare homogeneous and uniformly mixed energetic microspheres containing octogen and copper–aluminum composite particles.•The introduction of copper can promote the thermal decomposition of octogen.•Copper-aluminum composite particles instead of aluminum for the preparation of octogen composite microspheres can shorten the ignition delay and increase the combustion rate of the microspheres.