Integrating micro-ignitors with Al/Bi₂O₃/graphene oxide composite energetic films to realize tunable ignition performance

The integration of composite energetic films (CEFs) with various types of initiators can effectively adjust their performance and represents potential applications in microscale energy-demanding systems. In this study, the Al/Bi₂O₃/graphene oxide (GO) CEFs were successfully integrated into copper micro-ignitors by electrophoretic deposition, a low-cost and time-saving method. The effects of the Al/Bi₂O₃/GO CEFs with different GO contents on exothermic performance and ignition properties of micro-ignitors were then systematically investigated in terms of heat release, activation energy, ignition duration, the maximum height of the ignition product, and ignition delay time. The results showed that the addition of GO promoted more heat releases and higher activation energies of Al/Bi₂O₃/GO CEFs. The addition of ≤3.5 wt. % GO prolonged the ignition duration from 450 μs to 950 μs and increased the maximum height of the ignition product from about 40 mm to 60 mm. However, the micro-ignitors with more than 3.5 wt. % GO cannot be ignited, which suggested that GO played a contradictory role in the ignition properties of micro-ignitors and the controlled GO content was a prerequisite for improved ignition performance. The ignition delay time gradually extended from 10.7 μs to 27.6 μs with increases in the GO contents of Al/Bi₂O₃ CEFs, revealing that an increase in the weight ratio of GO leads to lower ignition sensitivity of micro-ignitors.