Enhancing Ignition Performance of NiCr-Based Microigniter by the In Situ Addition of an Aluminum/PVDF Nanoenergetic Film

Enhancing the ignition capability of microigniters, which are the most fundamental components of initiators and pyrotechnic devices, has become a critical issue that urgently needs to be addressed as the feature sizes become significantly smaller. The deposition of a nanoenergetic film on the surface of a microigniter is an effective strategy that uses the energy released from the violent combustion of the flim. To eliminate the premixed interfacial layer and improve the level of stored energy, a defect-free Al/PVDF nanoenergetic film with a thickness of 12.3 μm was in situ integrated with a NiCr-based thin film microigniter via electrospraying. The energy release characteristics of the prepared Al/PVDF films, including their morphological, thermodynamic behavior, and combustion performance, were systematically studied, and the results indicated that the optimal Al to PVDF mass ratio was 40/60. The ignition tests of the Al/PVDF-NiCr-based reactive igniters revealed that when a low-amplitude and long-pulse constant current flows through the NiCr-based igniter, the heat generated via the electrothermal process can effectively excite the Al/PVDF nanoenergetic film, whereas a high-amplitude and short-pulse input current is unserviceable. The high-temperature flame of the Al/PVDF film lasted for approximately 7 ms and could reliably ignite a B/KNO3 pellet loaded in an ignition train under contact or noncontact with a 1.1 mm gap. These results provide a practical approach for promoting miniaturization, integration, and high reliability of initiators and pyrotechnic devices.