Butterfly wing fans the fire: High efficient combustion of CWs/CL-20/AP nanocomposite for light ignited micro thruster using multi-channeled hierarchical porous structure from butterfly wing scales

To meet the requirement of miniaturization and integration of the micro thrusters based on the chemical fuels, high-energy density compound is an emerging material as the chemical fuel. However, it is still challenging to realize the high-efficiency, stable and self-sustaining microcombustion of the high-energy density chemical fuels. Herein, we report the high-performance microcombustion of CWs/AP/CL-20 composite with nanoscale 2,4,6,8,10,12-(hexanitrohexaaza)cyclododecane (CL-20) and oxidizer ammonium perchlorate (AP) confined in a self-standing carbonized butterfly wing scales (CWs) matrix. CWs with multi-channeled hierarchical porous structure provide a model architecture for loading of AP and CL-20. CL-20 is designed to serve as heat/pressure loss compensate agent due to its high-energy density, fast energy release rate and large amounts of gas release during combustion process. The combustion of CWs/AP/CL-20 is greatly enhanced due to the enhanced heat and mass transfer originating from the multi-channeled hierarchical porous structure and synergistic reactions between components at nanoscales, which is demonstrated as promising solid-propellant for the micro thruster. It is found that the sample with oxygen balance close to zero, which can be conveniently regulated by adjusting the mass ratio of CL-20 and AP, has the best microcombustion performance, resulting in a specific impulse of 383.5 N·s/kg.