Table 1.

Representative PNIPAM-ECHs based on their conductive components. “-” means not determined.

Gel Code	Conductive Components	Electrical Conductivity or Resistance	Applications	Reference
1	PANI or PPY	0.8 S/m	On-off switch	[65]
2	PANI or PPY	-	On-off switch, and pressure sensing	[101]
3	PANI	0.64 S/m	Repaired electric circuit, on-off switch	[70]
4	PANI	0.06 mS/cm	Actuator	[79]
5	PPY	-	Actuator	[78]
6	PPY	-	Actuator	[100]
7	MWCNTs	-	Scaffold	[104]
8	MWCNTs	1.5 MΩ	Sensor and actuator	[72]
9	MWCNTs	-	Photothermal therapy	[88]
10	Graphene	10 S/m	-	[106]
11	GO	-	On-off switch	[86]
12	rGO	-	Wound dressing	[90]
13	MXene	~1.1 S/m	Pressure sensing	[120]
14	MXene	~5.5 mS/cm	Human motion detection	[121]
15	MXene	-	Auto valve	[116]
16	Mxene		Actuator	[117]
17	Ag nanoparticles	-	-	[125]
18	Au nanoparticles	-	-	[126]
19	Au nanorods	-	On-off switch	[122]
20	Au nanorods	-	Drug delivery	[123]
21	Ions	4.40 S/m	Human motion detection	[128]
22	Ions	0.064 S/m,	Touch sensors	[77]
23	Ions	~0.5 S/m	Strain and pressure sensing	[127]
24	Ions	-	Human motion detection	[69]
25	Ions	-	Wireless human motion detection	[74]
26	MWCNTs and ions	0.19 S/m	Human motion detection and 3D printing	[43]
27	MWCNTs and PPY	35 S/m	Human motion detection and pressure sensing	[130]
28	Ions and rGO	5.6 mS/cm	Wound dressing	[89]
29	PEDOT:PSS and GO	0.08 S/m	Human motion detection	[75]
30	PEDOT:PSS and ions	-	Human motion detection	[73]