Table 2.

Summary of representative materials, substrates, mechanisms, and fabrication procedures.

Sensor Type	Materials	Substrates	Mechanism	Fabrication	References
Pulse Rate	Graphene Oxide	PET, PI	Conductometric	Transfer Printing	[22]
	PEDOT-PSS, PVDF-TrFE	PEN	Piezoelectric	Screen Printing	[23]
	PDMS, eGaIn	PDMS (tube)	Conductometric	Injection	[85]
	PVDF-TrFE, Al, Ag	PI	Piezoelectric	LBL	[82]
	Au	PDMS	Piezoresistance	Impregnation & Sandwiching	[79]
	Graphene Oxide, Au	Fabric (Facemask)	Humidity (variations)	Drop Casting	[40]
Respiratory/Breath	Graphite, SiO2	Cellulose Acetate	Humidity	Hand-painting	[38]
	Graphite	Paper	Conductometric	Hand-painting	[90]
	Silicon-nanocrystal	PI	Humidity	Spin coating	[98]
	CNTs	PDMS	Strain	Laser Scribing	[94]
	PVDF-TrFE	PDMS	Piezoelectric	Molding	[96]
	ZnO, Au	PI (nanoporous)	Impedance	E-beam, Sputtering	[39]
Alcohol/Acetone	ZnO, TiO2, Cu	Alumina	Chemiresistive	Screen Printing	[106]
	Au, ZnO	PI	Chemiresistive	E-Bean, Sputtering	[107]
	PEDOT-PSS	Paper	Transconductance	Inkjet Printing	[42]
	ITO, ZnO	PET	Chemiresistive	Drop Casting, Laser ablation	[105]
	ITO, P3HT, PVP	Glass	Chemiresistive	Drop Casting	[118]
Hydration	Graphene, Ag/AgCl	PMMA	Impedance	Wet Transfer, Dry Patterning	[117]
	Ag, PDMS	PDMS	Impedance	Drop Casting	[116]
	Ag/AgCl	PET	Electrochemical	Screen Printing	[114]
	PANI, PEDOT-PSS, CNTs	PDMS	Resistive	Spin coating, Molding	[131]
Temperature	CaCl2, Aliphatic Diols	PLA	Conductometric	Injection	[129]
	Graphene, Ag, PDMS	PET	Resistive	Transfer Printing	[128]
	Graphene/PEDOT-PSS	Polyurethane	Resistive	Inkjet Printing	[126]
Motion and Activity Monitoring	Pluronic F127, EAN	Ion-gel elastomer film	Resistive	Molding	[135]
	Galinstan, mass ratio: Ga/In/Sn = 68.5:21.5:10%	Silicone	Inductive	3D-Printing	[148]
	Carbon black	Polyurethane	Strain, Conductivity	Drop and dry	[134]
	Carbon, Ag	PDMS, Cotton	Strain	Impregnation, Casting	[138]
	MWCNT, Cu	PDMS	Strain	Casting	[137]
	MWCNTs,	Polyurethane	Piezoresistive	3D Printing	[147]
Pressure & Strain	MWCNTs, Al2O3	PI	Pressure/TFTs	ALD, Vacuum Deposition	[10]
	Cu, CNTs	PDMS	Piezoresistive	Casting	[12]
	Conductive self-healing hydrogel	PDMS	Piezoresistive	3D Printing	[155]
	SWCNT/paper, Au, PDMS	PI	Piezoresistive	E-beam evaporation	[15]
	ITO, diF-TESADT	PET	Pressure/OFETs	3D Printing	[154]
	Carbon	PDMS	Strain	Coating	[152]
Gas Sensors	AgNPs, Carbon, CNT	Silk	Chemirsistive	Spray & Drop Coating	[168]
	a-IGZO	PI	Output current (TFTs)	ALD, RF-Sputtering	[160]
	Reduced Graphene Oxide	PET	Chemirsistive	Drop casting, Spin coating	[22]
	Graphene, PbS Quantum Dots,	VHB acrylic 4910	Chemirsistive	Transfer Printing	[167]
	Ag, Au	PI	Chemirsistive	Inkjet Printing	[166]