Untethered Octopus-Inspired Millirobot Actuated by Regular Tetrahedron Arranged Magnetic Field. - Dai, Yuguo; Liang, Shuzhang; Chen, Yuanyuan; Feng, Yanmin; Chen, Dixiao; Song, Bin; Bai, Xue; Zhang, Deyuan; Feng, Lin; Arai, Fumihito (Adv. Intell. Syst., 2020)