Table 2.

Sensors used in electronic textile.

Type	Material	Format	Mechanism	Ref.
Motion	Rigid electronic	Inertial motion capture	magnetometers, accelerometers, and gyroscopes	[56]
	Bending sensor	Optical fiber (Bragg grating)	Optics	[22]
	Carbon black dip-coated co-polyester elastomer or spandex filament	Sensors attached to t-shirt	Strain-induced disruption and connection of conductive pathways affects electrical resistance (piezoresistive).	[56]
	Machine knit elastomeric and conductive (80% polyester, 20% stainless steel) multifilament yarns	Rehabilitation glove	Strain affects contact resistance (Holm’s contact theory)	[44]
	Flexible, non-crocking reduced graphene oxide fabric through dip coating and nickel electroless plating	Strain sensor	Strain affects resistance	[54]
	Conductive polymer filaments	Strain sensor	resistance change in paired (stretched/relaxed) sensors	[59]
	Hand-knit together cotton yarn and wire	Inductor coils	Increasing radius increases inductance	[60]
Physiology	Electrode	Carbon or conductive yarns (stainless steel)	Change in resistance due to stimuli	[50]
	highly conductive, nitrogen-doped working electrodes	carbonized or graphitized woven silk fabric	Circuit converts signal into data for mobile display Current: glucose, lactate Potential: sodium, potassium	[61]
	“wet” electrode (sweat is electrolyte)	conductive knit fabric (Shieldex Fabric by Statex) knife-coated with a conductive paste	Measure Biopotential	[62]
	(EEG) sensor	layers of conductive and sweat absorbent fabrics	Measure Biopotential (~100 μV)	[63]
	Blood oxygenation	Rigid electronics	oxygenated and deoxygenated hemoglobin absorb different amounts of light	[52]
	Antennas	Conductive fabric attached to silicone rubber substrate	Resonance frequency interference between antennas corresponds to brain atrophy and lateral ventricle enlargement	[64]
Environment	Temperature sensors	printing conductive inks	change resistance in response to temperature [22]	[65]
	Temperature sensors	weaving electronic strips into textile	change resistance in response to temperature [22]	[65]
	Temperature sensors	encapsulating temperature sensor in yarn core	change resistance in response to temperature [22]	[65]
	Humidity sensor	poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) on a substrate of polyacrylonitrile nanofibers	materials change conductivity in response to moisture	[22]
	flexible ammonia sensor	cotton yarn coated with carbon nanotube ink	exposure to chemical changes resistance, “chemiresistor”	[66]
	multimodal	“Carbon Nanotube Paint” coated degummed silk fiber	electrical resistance changes with stimuli	[67]