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Thermosetting polymers are stable, high-performance materials that are crosslinked by heating and curing at a specified temperature. These materials are mechanically strong and highly resistant to thermal and chemical degradation, such that thermoset composites are a popular choice for applications ranging from battery frameworks to aerospace and automotive frames. [1] Current manufacturing processes for thermosetting epoxy resins include molding and curing of the matrix in a hightemperature oven, which is energy, labor, and time consuming, and sets limits on achievable part geometries and process times. [2,3] Existing methodologies to form epoxy composites include stacking one layer over the other to make 3D parts. [4] The ability to 3D print these multilayered structures would allow for the free-form fabrication of complex geometries, eliminating the additional cost of ovens and specific molds for each part. Additive manufacturing has been extensively used to 3D print thermoplastics [5][6][7] and metals. [8][9][10] A development of such an on-demand, rapid production technique could facilitate a distributed manufacturing economy for high-performance composites. [11] There has been limited research in the field of printing thermosets from a reservoir of resin. Selective curing of photocurable resins on the upper interface of liquid reservoirs using UV light has been reported previously to print 3D structures. [12,13] The materials used to make structures using this method are at least partially made of UV curable resins rather than conventional commercial thermosets. Apart from this, a handful of technologies have been developed for the additive manufacturing of thermosets. Extrusion-based printing of thermosets has been made possible by printing inside a thixotropic support bath, followed by extraction from the bath and curing in an oven. [14] Other studies have shown that direct ink writing coupled with UV-assisted curing can be used to 3D print light-sensitive resins. [15,16] Studies have also added viscosity-modifying agents to make the resin shearthinning. This allows the resin to be printed via direct ink writing such that it can retain its shape after being extruded, before being transferred to an oven for curing. [17][18][19] Additive manufacturing of thermosets via frontal polymerization has been explored to print complex shapes but is restricted by the limited number of resin chemistries that can be printed using this method. [20,21] It is highly desirable to develop an out-of-oven curing methodology that would allow for selective curing and 3D printing of

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A reliable method is presented for the computation of the propagation constants and the corresponding hybrid modal fields in multilayered planar dielectric stacks comprising multiple anisotropic conducting sheets. The appropriate dispersion functions (DFs) are formulated and evaluated using a numerically stable scattering matrix methodology. The roots of the DFs are computed by the Cauchy integration method with automatic differentiation of the DF.