“…Hydrogels with ordered anisotropic structures [1,2], similar to biological tissues [3-6], have promising applications in the fields of actuators and sensors [7][8][9]. To build the anisotropic structure in hydrogels, self-assembly through intermolecular interactions was used [10], and external field effects, such as electrical field [11], magnetic field [12][13][14][15][16][17], mechanical-strain-induced (stretch) [18][19][20][21][22][23][24][25][26][27][28], shear-force-induced [29,30] and directional freezing [31], have been employed. Currently, hydrogels prepared by the above mentioned methods achieve anisotropic properties [7][8][9], such as anisotropic optical properties [14, 22,32], mechanical performances [18], actuating abilities [14,33] and electrical conductivity [11].…”