Additive manufacturing of self-sensing parts through material extrusion

Figures & data

Figure 1. Test specimen Type A (No. of grid lines = 1).

Figure 2. Test specimen Type B (No. of grid lines = 38).

Table 1. Global additive manufacturing parameters.

ISO/ASTM AM Method	Machine	Software	Material		Layer thickness [mm]	Post-processing
			Thermoplastic matrix	Reinforcement
Material Extrusion	Anisoprint A4	Aura 1.27.2	PETG	Continuous carbon fiber + Continuous Copper wire	Thermoplastic matrix: 0.17 mm Reinforcement: 0.34 mm	Manual removal from build platform

Table 2. Processing parameters of continuous carbon fiber and continuous copper wire.

Description	Continuous carbon fiber	Continuous copper wire
Diameter [mm]	0.35	0.35
Build plate temperature [^oC]	60	60
Z-lift on restart [mm]	0.5	1
Fiber extrusion speed [mm/sec]	10	1
Restart pause [sec]	1	25
Finish ironing distance [mm]	20	20
Plastic retract	Yes	Yes
Fan speed [%]	50	50
Fiber feed rate [%]	100	125
Printing speed coefficient	0.5	0.2

Figure 3. Flexural fixture for Type A specimen.

Figure 4. Flexural fixture for Type B specimen.

Figure 5. Additive manufacturing of Type B specimen with (a) continuous copper wire and (b) continuous carbon fiber, and (c) the end-use specimens.

Figure 6. Self-sensing capability of Type A specimen embedded with CCW.

Figure 7. Self-sensing capability of Type B specimen embedded with CCW.

Figure 8. Self-sensing capability of Type A specimen embedded with CCF.

Figure 9. Self-sensing capability of Type B specimen embedded with CCF.

Figure 10. Linear regression of fractional change in electrical resistance as a function of force and deflection for Type A and Type B specimens. (a)Type A: CCW (b)Type B: CCW (c)Type A: CCF (d)Type B: CCF

Figure 11. Flexural stress in the outer surface at midpoint as a function of flexural strain.

Table 3. Piezoelectric properties of the test specimens based on statistical evidence.

Description	Stimulant	Specimen Type	Sensitivity	Sensing Tolerance	R-squared	P-value
Continuous copper wire	Deflection	A	kD = 534.6 [10^−6 × mm^−1]	±2.9%	94.3%	<0.005
		B	kD = 202.4 [10^−6 × mm^−1]	±2.4%	94.5%	<0.005
	Force	A	kp = 47.4 [10^−6 × N^−1]	±3.0%	93.9%	<0.005
		B	kp = 122.4 [10^−6 × N^−1]	±2.6%	93.8%	<0.005
Continuous carbon fiber	Deflection	A	kD = 1559.6 [10^−6 × mm^−1]	±16.4%	35.3%	<0.005
		B	kD = 39.7 [10^−6 × mm^−1]	±3.2%	90.7%	<0.005
	Force	A	kp = 124.7 [10^−6 × N^−1]	±17.47%	32.0%	<0.005
		B	kp = 21.3 [10^−6 × N^−1]	±3.2%	90.8%	<0.005

Data availability statement

The data that support the outcomes of this study are available from the corresponding author upon reasonable request.