Table 1. Compilation of References of Shape Memory Composites Activated with an Electric or Magnetic Field.

SMP	filler	ς	ρe (Ω m)	activation	activation magnitude	T reached (°C)	tR (s)	comments	ref
PCL	MWCNT	3 wt %	0.15–0.6	electrical	controlled resistive heating (0.6–15.7 mA)	60	130	1W-SM and 2W-SM effects; RF > 96.7% and RR > 88.9%; variable electric current to achieve constant temperature and constant heating and cooling rates; nonlinear evolution of ρe within shape memory cycle	(101)
PU	MWCNT + Fe3O4	30 wt % Fe3O4 +0.25–1 wt % MWCNT		magnetic	29.7 kA/m at 45 kHz	>45	60	RR >95%	(178)
PU/SM-PU	CB	1–5 wt %	5 × 10–2 Ω m for 5 wt %; 10–3 Ω m for 3 wt %	electrical	100 V		25	2W-SM; RR 99.8%	(179)
PU	MWCNT	5 wt %	∼1 Ω m	electrical	60 V	100	10		(180)
EP	MWCNT	0.2 wt %	1–10 Ω m	electrical	126–265 V	200–250	<300	sequential recovery	(102)
EP	MWCNT	30 wt %	47 Ω m	electrical	12 V	>55	22		(98)
EP	rGO	0.5 wt %	0.025 Ω m	electrical	10 V	>100	10	RF = 95% and RR = 98%; electrical recovery	(181)
PLA/PU	MWCNT and CF	6 wt %		electrical	10 V	>70	25	RR = 94%; negative Poisson ratio	(182)
PVAl	MWCNT	5–30 wt %	0.52 Ω m for 30 wt %	electrical	45–120 V	>74	35		(183)
PCL	MWCNT coated Fe3O4			magnetic	6.8 kA/m at 20 kHz	T increase of 17.2	120	alignment of Fe3O4-coated MWCNT due to magnetic field 0.2 T; increase of elastic modulus by almost 100% but reduction of max elongation	(184)
PCL	MWCNT	3 wt %	0.05 Ω m	electrical	0.1 W	∼50		analytical, numerical, and experimental investigation	(100)
BR	MWCNT and CB	0–15 phr MWCNT or 0–30 phr CB	10–2 Ω m for 15 phr CNT or 30 phr CB	electrical	50 V	110 after 15 min at 50 V	900	lower ρe and higher RF and RR for CNT than CB	(87)
PU	Fe3O4	0–9 wt %		magnetic	250 A/m at 20 kHz	>52	35	RR decrease with ς, slight RF increase with ς	(185)
PBS–PEG	CNT	0.2–1 wt %	7.05 Ω m for 1 wt %	electrical	20–120 V	85 at 70 V for 1 wt %	55	CNT reduced ductility	(186)
PU	CNF	1–7 wt %	560 Ω m for 7 wt %	electrical	100–300 V	25–55		χc, RF decrease with ς of CNF; elastic modulus increase with CNF ς	(187)
PU	CNT	3 wt %	0.037 Ω m	electrical	50 V	>40	40	different preparation techniques and effect of dispersion and electrical properties	(93)
PU	G sheet	1–8 wt %	1.17 Ω m for 8 wt %	electrical	65–80 V	>70	8	2W-SM; study mechanical properties; RF = 95%; RR = 93%	(111)
PU	CNT	4 wt %		electrical	40 V	100 cross-linked CNT	50	CNT covalently bonded to PU; increase RR and RF for cross-linked CNT (>10%)	(92)
PU	rGO	0–2.5 phr	0.4 Ω m for 2.5 phr	electrical	50 V	64 for 2.5 phr	120	Tg and mechanical properties increase with ς; ductility increase with cycles; RR decreases with ς	(114)
EOC	CB	0–38 wt %	0.08 Ω m for 17 wt %	electrical	5–15 V for 17 wt %	40–160	60	two different CB fillers; lower RR for higher ς	(85)
PU	rGO + Fe3O4 and γ-Fe2O3	3 wt % GO + 7 wt % Fe3O4		magnetic	287 kHz with 300A in coil	70 for mixture, 60 for hybrid	60	Young modulus doubled from hybrid to only Fe3O4	(188)
PU	Ni powder chains	0–20 vol%	0.005–0.01 Ω m for 20%, 104 for 4%	electrical	6 V	55	90	alignment magnetic field; decrease Tg with ς	(142)
PU	CB with and without 0.5 vol% Ni	4–10% CB	0.1 Ω m for 10% CB + chained 0.5% Ni	electrical	30 V	80	120	ρe increases with number of cycles	(189)
PVAl	CNT and G	20 phr GO and 4–16 phr CNT	0.1 Ω m for 20 GO + 16 CNT	electrical	60 V	100 max (normally 60)	120	ρe decreases with bending angle	(190)
PS	CNT	1.47–7.02 wt %	0.01 Ω m for 7.02 wt %	electrical	35 V	>85	80	RR ≈ 100%	(96)
PU	GNP	1–3%	4 Ω m for 3% GNP	electrical	75 V	100 for 3%	60	χc, elastic modulus, RF and RR increase with ς; strength, Tg, and Tm decrease with ς	(191)
EP	Ag decorated rGO and CF mat	2–4 wt % rGO and 11.6% CF	2.3 × 103 Ω m	electrical	8.6 V	100	36	RR = 99%	(192)
PS	MWCNT nanopaper	1.47–7.02 wt %	0.008 Ω m for 7.02 wt %	electrical	0.6 A	>62	300	RR = 98%	(95)
EP	CNF	9.18 wt %?	0.03 Ω m	electrical	10–20 V	>50	2.1	increase elastic modulus above Tg, increase κ	(193)
PU	MWCNT	3–7 wt %	12 Ω m for 3 wt %	electrical	40 V	>70 in 10 s	9	Young modulus increase by 50%; RR > 98%; Tc increase with ς	(194)
PU	Fe3O4	0–10 wt %		magnetic	30 kA/m at 258 kHz	70 at 150 s 12.5 kA/m 258 kHz	22	magnetic heating depends on geometry; for high ς, RF and RR higher for magnetic actuation	(135)
PK BMI	MWCNT	8 wt %	∼ 0.06 Ω m	electrical	20–50 V	40–140		RR = 90% by 40 V; self-healing	(195)
PU	MWCNT	3–10%	0.9 Ω m	electrical	9.5 mA	32			(164)
PU	GO	0–20 phr	>7 × 102 Ω m	electrical	100–200 V	<60			(196)
EP	Fe3O4 coated with oelic acid	1.5–8 wt %		magnetic	30 mT at 293 kHz	T increase of +25	60		(133)
PPC/PLA	MWCNT	1–3 phr	0.1 Ω m for 3 phr	electrical	20–30 V	130 max for PPC/PLA (50/50) 3 phr at 30 V	30	max tensile strength and strain at break increased with ς at room temperature; At 50 °C strength decrease with concentration; RR = 97%	(197)
PLA/PU (70/30)	CB	0–8 phr	∼0.4 Ω m for 8 phr	electrical	30 V	98 for 8 phr	80	RF = 90%; RR increase from 59% to 85.9% for 8 phr CB; conductivity ∼1 order of magnitude higher for PLA/PU(70/30) than for PLA	(198)
PU	CF/PU yarn fabric	10.9% CF	1 × 10–3 Ω m	electrical	6 V	87	80	RR = 99.3%; applications of deployable structure	(82)
PEVA	CNF	0–15 wt %	0.204 Ω m for 15 wt %; 5 × 109 Ω m for 3 wt %	electrical	60 V	100 after 25 s		2W-SM; RR decreases with ς	(199)
PU/PCL	modified MWCNT	2–10 wt %	1 Ω m for 10 wt %; 102 Ω m for 4 wt %	electrical	40 V	>50	15	Tg of PLA increase with ς; Tgof PU decrease with ς; Tcdecrease with ς	(200)
PU/PVDF (90/10)	modified MWCNT	0–10 wt %	50 Ω m for 10 wt % pristine CNT; 4 Ω m for 10 wt % modified CNT	electrical	40 V	T rise of +40	15	κ × 4 by adding 10 wt % MWCNT; increase 10% tensile strength and decrease 100% elongation at break for surface-modified MWCNT than pristine; RR decrease with cycles faster for modified than pristine CNT	(94)
PU	Fe3O4	0–40 vol%	106 Ω m for 40 vol%	magnetic	4.4 kA/m at 50 Hz	50	1200	electric percolation at 30 wt %; Cp decrease with ς; κ increased by 0.4 for 40 vol %	(201)
PEVA and PU	FE2O3	0–13.6 wt %		magnetic	15–23 kA/m	100 for PEVA; 108 for PU			(202)
PDL	Fe3O4	5–11 wt %		magnetic	7–30 kA/m at 258 kHz	100	180	decreased RF (95% to 90%) and increased RR (95% to 97%) for increased ς	(203)
EP	CB	0–10 wt %	200 Ω m for 10 wt %	electrical	3.5 W constant power	65	<200	ρe vs ε during elongation and recovery	(204)
PVA	GNP	1.5–4.5 wt %	0.04 Ω m for 4.5 wt %	electrical	50–70 V		2.5	elastic modulus increases by 1 order of magnitude from 0 to 4.5 wt %; Tg decrease with ς	(115)
PU	PPy	8–21%	0.105 Ω m	electrical	40 V	70	<30	Tm decrease with ς	(205)
PCL DMA	Fe3O4	2–12 wt %		magnetic	300 kHz, 5 W	43	20		(206)
PLA/PU (50/50)	CNT	1–5 wt %	0.33 Ω m for 5 wt %	electrical	50 V	50–70	<150	decrease RR (13% smaller) in 5 wt %; faster shape recovery with electrical heating than conventional; higher RR with electrical heating than conventional	(207)
EP	MWCNT nanopaper	40 wt %	3 × 10–3 Ω m	electrical	0–6 W	20–170	20	curing with resistive heating 105 °C after 40 s at 4.6 V; recovery at 76 °C	(97)
PE	CNF	0–11.6 vol%	0.1 Ω m for 11.6 vol%	electrical	1–40 V	100–110	100	Tc and elastic modulus increase with ς; Tm decrease with ς	(208)
PCL/MA (50/50)	MWCNT	0–10 phr	0.0384 Ω m	electrical	40 V	>70	56		(90)
PU	GNP			electrical	10–30 V	60 at 10 V	20		(209)
PCO/PE	MWCNT	8–15 vol%	0.0105 Ω m for 10 vol%	electrical	150 V	>120 after 2 min	90	triple SM effect; MWCNT dispersed in PCO; chemical cross-linking increases ρe due to agglomeration of fillers	(210)
SBS/LLDPE	CB	0–25 wt %	1.08 Ω m for 1 wt % CB; 7.4 × 10–2 Ω m for 25 wt % CB	electrical	0–120 V		60	elongation at break decrease by 50% from 0 to 25 wt % CB; tensile strength increase by >50%; recovery at 40 V	(211)
EP	rGO		0.0027 Ω m	electrical	1–6 V	35–240	5	bending	(110)
PEVA/PCL	MWCNT	5 wt %	0.0205 Ω m	electrical	20 V	97	12	recovery at 30 V	(212)
PU	CNT	10 to 50 layers	22.96 Ω m	electrical	40 V	90	30	CNT layers at different locations; RR = 100% at 40 V; localized and selective actuation	(99)
EP/CE	GNP	0.8–2.4%	11.3 × 10–2 Ω m for 2.4%	electrical	20–120 V		98	strength increased by 25% for 1.6 wt %; recovery at 60 V	(213)
EP	Ag-CF	5.4 wt %, 1.8 wt %	95.1 Ω m for 5.4 wt %; 1 × 106 Ω m for 1.8 wt %	electrical	60–120 V		60	RF increase with ς; RR decrease with ς	(81)
EP	MWCNT and CB	1.9 wt % total	2 × 105 Ω m for 0.8 wt % MWCNT	electrical	225 V	>80	570	RR = 99%	(214)
PLA/PU (70/30)	MWCNT and CB	3–5 phr CB and 0–2 phr MWCNT	<0.1 Ω m for CB 5 phr and >1 phr MWCNT	electrical	30 V	70 °C	100	70 °C after 100 s for 3 phr CB and 1 phr CNT; RR = 0	(215)
PPDO–PCL/PU	Fe3O4	0–10 wt %		magnetic	7–30 kA/m at 256–732 kHz	65			(136)
PMMA–PEG	Modified Fe3O4	1–5 wt %		magnetic	100 kHz, 8 kW	40.4	59	T rise 4 °C for-surface modified Fe3O4 than for pristine; RF = 90%; RR = 95%	(216)
PCL	modified MWCNT	0–9 wt %	20 Ω m for >7 wt %	electrical	50 V for 5 wt %	70	120	decrease RR with ς	(217)
PCL-Py	SWCNT	2 wt %	3.6 Ω m	electrical	50 V	65	20	increase RR with ς	(104)
MA-based thermoset	Fe3O4	0–2.5 wt %		magnetic	0.33 mT at 297 kHz	50	40		(218)
PS	MWCNT and CB	1 wt % MWCNT and 10–15 wt % CB	0.03 Ω m for CB. 0.025 Ω m for CB+CNT randomly oriented. 0.0075 Ω m for CB+CNT chained	electrical	25 V	>95	75	MWCNT in chains, reduction of ρe by more than 1 order of magnitude; ρe increases with number of shape memory cycles	(107)
acrylate	NdFeB and Fe3O4	15 vol % of each		magnetic	40 mT at 60 kHz (to heat up Fe3O4) + 30 mT at 0.25 Hz to actuate beam	100 (and above) in 40 s		dual magnetic field activation; elastic modulus increases linearly with ς; RF = 95%; RR = 100%	(141)
PLA	Fe3O4	10–40 wt %		magnetic	30 kA/m at 268 kHz	>60	>200	nonmonotonic evolution of RR, modulus, tensile strength, and elongation at break with ς	(132)
Nafion	Fe3O4	15–25%		magnetic	Power 50–100%	internal T 50–110, surface T < 40	16	surface modification of Fe3O4 to improve distribution	(219)
PCL/PU	GNP	0–10 wt %	∼1 Ω m for 10 wt %	electrical	10–40 V	60 for 10 wt % at 10 V; 100 for 10 wt % at 30 V	60	5ecovery within 1 min for 7 wt % at 30 V; faster heating and recovery for higher ς; Tg, χc, viscosity increase with ς; Tmand Tc decrease with ς	(220)
PLA	PPy		0.028 Ω m	electrical	15–40 V	120 for 40 V	2	microfiber membrane PPy coated; worse mechanical properties with Ppy ρe depends on polymerization time and temperature	(221)
PCLA	GO	4.86–13.29 vol %		electrical			2.5	RR = 100%	(222)
PU/EP	G and CNT	0.8–3 wt % CNT and 2–12 wt % graphene	0.31 Ω m for 12 wt % graphene	electrical	100 V for 8% graphene and 3%CNT	60	150	compressive strain; densification at ε > 70%; 2% permanent deformation after 100 cycles	(223)