Table 2.

Various types of printing methods used for the fabrication of flexible/stretchable tactile sensors.

Year	Fabrication technique	Printer used	Minimum detail	Printed component	Transduction principle	Ref.
2019	Fused filament fabrication (FFF)	Customized FFF printer	—	Sensing element	Piezoresistive	[236]
2019	Fused filament fabrication (FFF)	MakerBot 2X replicator	200 μm	Sensing element, sensor body	Piezoresistive	[237]
2019	Fused filament fabrication (FFF)	Customized LulzBot	—	Sensing element	Capacitive	[181]
2019	Aerosol jet printing	Self-built printer	~10 μm	Sensing element	Piezoresistive	[238]
2019	Direct ink writing	Self-built printer	—	Sensing element	Piezoresistive	[239]
2018	Fused filament fabrication (FFF)	Standard FFF printer	—	Sensor body, sensing element	Piezoresistive	[130]
2018	Inkjet printing	Enjet Corp., Korea	60 μm	Sensor electrode	Piezoresistive	[240]
2018	Inkjet printing	Canon IP100	—	Sensing element	Capacitive	[213]
2018	Direct ink writing	Self-built printer	60 μm	Sensing element	Piezoresistive	[149]
2018	Direct ink writing	Glass micropipette	—	Sensor electrodes	Capacitive	[82]
2018	Direct ink writing	Home-built 3D printer, Cura Ultimaker	400 μm	Sensing element	Capacitive	[191]
2018	Direct ink writing	Custom-built printer	—	Whole sensor	Piezoresistive	[212]
2018	Direct ink writing	Self-built printer	300 μm	Sensing element	Piezoresistive	[241]
2018	Direct ink writing	Home-built 3D printer	400 μm	Sensing element	Capacitive	[242]
2017	Fused filament fabrication (FFF)	MakerBot 2X replicator	100-300 μm	Sensor body, sensing element	Piezoresistive	[243]
2017	Fused filament fabrication (FFF)	MakerGear M2	50 μm–0.25 mm	Sensing element	Piezoresistive	[244]
2017	Inkjet printing	ProJet 5500X	~30 μm	Sensor body	Piezoresistive	[9]
2017	Inkjet printing	—	—	Sensor electrode	Piezoresistive	[245]
2017	Inkjet printing	MicroFab jetlab II	—	Dielectric layer	Capacitive	[198]
2017	Inkjet printing	jetlab4, MicroFab	170 nm	Sensor element	Piezoelectric	[246]
2017	Direct ink writing	Custom-built 3D printer	—	Sensor body, sensing element	Piezoresistive	[231]
2017	Direct ink writing	Self-built	—	Sensing element	Piezoresistive	[247]
2017	Direct ink writing	Self-built printer	Trace width—100 μm	Sensing element and electrodes	Capacitive	[109]
2017	Electrohydrodynamic (EHD)	Self-built printer	15 μm	Sensing element	Capacitive	[235]