Table 2.

Material fabrication details of polymeric metamaterials.

Study	AM Technique	Fabrication Challenge	Fabrication Solution
He et al. [100]	DLP	Strut deformation of polymer-derived ceramic metamaterials during the pyrolysis process	Introduction of 20 wt.% hydroxyl silicone oil prevented the deformation of struts with 0.5 mm thickness
Zhao et al. [92]	FDM	Polymeric metamaterials with high ceramic yield are so brittle to be fabricated using FDM	Improving the formability and printability of polycarbosilane using ≤5 wt.% of polypropylene
Chen et al. [111]	Micro-SLA	Cross-contamination between two different feedstocks during multi-material additive manufacturing	Integrating a self-cleansing robotic dispenser into the 3D printer for cleaning residue monomer at each layer before a new feedstock is perfused
Wang et al. [87]	FDM	Bond and joint failure between a corrugated core and face sheet panels in corrugated structures	Fabricating the structures using single-stroke integrated manufacturing for strengthening the connection between the core and the face sheet panels
		Shape retention problem during post curing procedure	Utilization of liquid deposition modeling to deposit silicon rubber between the gaps of the unit cells
Clarkson et al. [96]	DIW	Limited number of commercial printing inks with certain viscosity constrains and shear-thinning requirement	Modifying the conventional DIW procedure to expand the range of printable materials through including UV-assisted reactants in the slurry
Essmeister et al. [115]	SLA	Cracks appearing when printing millimeter scale lattice structures made of SiOC PDC	Incorporating SiC particulates within SiOC matrix to produce crack-free millimeter scale features
Verma et al. [116]	MJF	Powder entrapment zones in plate/shell-based lattice metamaterials	Introducing a honeycomb shaped structure with ventilated holes to eliminate power entrapment