Table 1.

Different methods for fabrication of polymer-MN along with advantages and disadvantages of each method.

Method	Description	Advantageous	Disadvantageous	Ref.
Micromolding	Uses cutting tools to fabricate microscale arrays	Easy production, cost-efficiency, potential for industrialization	Time-consuming,limits the use of sensitive drugs	[42]
Droplet-born air blowing (DAB)	The 3D microneedles are shaped from polymer droplets through applying the air blowing	Mild preparation condition, easy control of drug loading	Not applicable in producing complexshapes	[43]
Drawing lithography	A strategy (thermal, magnetorheological, or UV) for the fabrication of a MN directly from 2D planar polymers	Fabrication of ultrahigh-aspect ratio (UHAR),stepwise controlling	Poor reproducibility, limits the use of sensitive drugs	[44]
Electro-drawing	MN is fabricated by applying electrical discharges	MN with complex shapes can be manufactured without deformation	The preparation device is complicated, requires conductive materials, the cost is high	[45]
Photolithography	A fabrication strategy based on the pattern parts of a thin film of an agent	Cost effective, production of smaller featuresize	Increased cost for new technology,complexity, concern about the reliability	[46]
Continuous liquid interfaceproduction (CLIP)	A continuous, rather than layer-by-layer, approach to manufacture MN	The preparation method is simple and fast, various shapes of MN can be prepared	Need light curing, not suitable for some sensitive drugs	[47]