“…Solid microarrays are also utilized as master molds to fabricate inverse or negative molds (also known as production molds) for the manufacturing of other MAP types, such as dissolvable, porous, and hybrid MAPs [ 216 , 226 , 245 , 256 ]. Traditional microfabrication techniques (e.g., etching and photolithography) have been broadly used to create solid MAPs; however, new approaches, such as micromachining, diamond micromilling, and most recently 3D printing, have emerged to address the material, geometry, ramp-up time, and cost limitations of cleanroom-based microfabrication strategies [ 216 , 228 , 229 , 257 ]. Notably, 3D printing, or additive manufacturing, approaches have drawn considerable recent attention due to their unprecedented design flexibility, which enables fabrication of more innovative microarray geometries [ 230 , 231 , 258 , 259 ].…”