Versatile Motion Generation of Magnetic Origami Spring Robots in the Uniform Magnetic Field

Sishen Yuan, Sifan Cao, Junnan Xue, Shijian Su, Junyan Yan, Min Wang, Wenchao Yue, Shing Shin Cheng, Jun Liu, Jiaole Wang, Shuang Song, Max Q.-H. Meng, Hongliang Ren

Abstract: Magnetic soft robots have attracted widespread attention for their untethered, remotely operated, and compliant deformation characteristics. Earlier work has demonstrated magnetic origami robots' diverse locomotion capabilities. This letter will focus on the motion generation and open-loop control of an untethered magnetic flexible robot with a stretch-twist coupling origami spring (OS) skeleton only using uniform magnetic field control. We investigate the associated motion generation mechanism and the corresponding control signals for the magnetic spring robot (MSR). The MSR can perform in-plane crawling ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Worm Crawling</i> ) and perpendicular in-plane crawling ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Crab Crawling</i> ) under two-dimensional magnetic signal inputs. Moreover, the OS's stretch-twist coupling characteristic is utilized to achieve axial <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Rolling Motion</i> with axial magnetization configuration. We further experimentally tested the performance of three motions with average normalized velocities of 0.34 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.039(body length/s), 0.054 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.0066(body length/s), and 1.46 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.069(body length/s), respectively.