Nanothermites have shown the potential to controllably fracture substrates in applications such as electromechanical systems security. In prior work, both equivalence ratio and material formulation have been varied to tailor fracturing performance. In this paper, material confinement was utilized to further tailor the fracturing performance of aluminum bismuth (III) oxide (Al/Bi2O3) and aluminum copper (II) oxide (Al/CuO) nanothermites. These nanothermites were selectively deposited onto representative substrates through inkjet printing. Al/Bi2O3 nanothermites were prepared over a range of equivalence ratios and showed a range of resulting fragmentation, with a maximum near the equivalence ratio of ϕ=2. Burning rate measurements correlated with the trends seen in these experiments. All of the previous attempts at fragmenting a substrate using unconfined Al/CuO were unsuccessful. The prepared Al/CuO nanothermites at stoichiometric conditions resulted in fractured silicon substrates when confined. These results demonstrate the ability of confinement to further tailor the fracturing performance of nanothermites.

The inside back cover picture shows the relationship between burning rate and equivalence ratio for aluminum bismuth (III) oxide nanothermite and highlights the correlation between this relationship and the ability of the material to controllably fracture silicon substrates when the material is confined. Details are discussed in the article by Eric R. Westphal et al. on page 47 ff.

Electrodes fabricated from electronically active polymers offer some benefits over those fabricated with common metals, including an appreciable resistance to corrosion and lower density. These benefits, and potentially others, manifest the advantages of using conductive polymers in lieu of metals for the mass production of ignition systems. In this work, spark gap igniters were fabricated using a potentially low‐cost, roll‐to‐roll compatible process utilizing the doped conductive polymer polyaniline as the electrode material. Subsequently, nanothermite was printed on the spark gap igniters between the organic leads and ignited using a high voltage source to demonstrate the effectiveness of the device. All of the igniters successfully fired with a mean spark over voltage of 3.14 kV. In addition, all of the igniters with deposited nanothermite successfully ignited the material. Accordingly, this work outlines the materials and processes required to develop organic‐based spark gap igniters and establishes a baseline for future work related to the metal‐free ignition of energetic materials.