Table 1.

Summary of advanced material strategies for additive manufacturing.

Material Class	Materials		AM process	Applications
Conductive materials	Metal-based materials	Liquid metals, metal nanoparticles, In stu reactive metal inks.	Material jetting [26,43] Material extrusion [24,25,32,33,35,36,37,39,40,41] Directed energy deposition [29] EHD printing [19,27,28,30,34,38]	metal channels, interconnects, electrodes, electronics, sensors, microbatteries.
	Other conductive materials	carbon-based materials, lithium-ion zinc.
Biomaterials	Biopolymers	PLA, PCL, PLLA, PEO, PVP.	EHD printing [48,55,56,57,58,67,76] Material extrusion [50,61,63,64,65,66,74] Vat photopolymerization [62] Cell printing [68,69,70,71,72,73]	bio-scaffolds, fabrication of tissues and organs, drug release, microfluidic devices, organ-on-a-chip applications.
	Hydrogels	Methacrylate gelatin (GelMA), collagen, alginate, hydrogel blends.
Smart materials	Shape-shifting materials	shape-shifting glasses, shape-shifting solutions, shape-shifting proteins, shape-shifting hydrogels.	4D printing [84,85] Material extrusion [86,87,91,92] Material jetting [88] Directed energy deposition [89] two-photon photolithography [90] digital projection printing [93] projection micro-stereolithography [94] vat photopolymerization [95]	Soft microrobotics, Biomedical engineering, Drug delivery, Piezoelectric devices.
	Piezoelectric materials	Barium titanate (BaTiO3, BTO), Polyvinylidene fluoride (PVDF).