Drawing Lithography: Three‐Dimensional Fabrication of an Ultrahigh‐Aspect‐Ratio Microneedle

Drawing lithography is a novel fabrication technique in which a thermosetting polymer is directly drawn from a two-dimensional solid surface without the need for a mask and light irradiation (see figure). Drawing lithography differs from traditional lithography techniques, such as photolithography, in that it is based on the inherently planar geometries of a two-dimensional substrate in a three-dimensional microstructure.