Programmed Magnetically-Triggered Ultrathin Soft Robots with Fast Actuation Speed


Programmed Magnetically-Triggered Ultrathin Soft Robots with Fast Actuation Speed

Wang, X.; Ge, J.; Canon Bermudez, G. S.; Fassbender, J.; Makarov, D.

Soft robots have been designed and developed to fulfil the demands of better deformability and adaptability to changing environment [1-2]. These soft robots could be made of various stimuli responsive materials that can be actuated by magnetic field [3], light [4], temperature [5], electric fields [6], chemicals [7], pressure [8], etc. In contrast to other actuation mechanisms, magnetic fields are appealing for numerous application scenarios (e.g. environmental, biological, medical), where the benefits stem from their long range penetration, easy accessibility and controllability [2]. There are already impressive demonstrations of magnetically triggered actuators performing as walkers, swimmers and grippers [9]. However, most of these robots are bulky (0.2 mm thick) [11], reveal low actuation speed (2.7 s deflection time) [11] and not sufficiently soft to demonstrate reversible large scale actuation amplitude (less than 1 micron) [12]. Furthermore, they require rather large magnetic fields (42 mT) [13] for actuation, which limits their application potential.

Here, we present an ultrathin and lightweight soft robot that can be actuated in a tiny magnetic field of 0.2 mT reaching full actuation amplitude with reaction times of 10 ms only. The Young’s modulus of the developed magnetic elastomer (NdFeB particles are dispersed into a PDMS host) goes down to remarkable 5 MPa while still maintaining stretchability levels of 50%. The weight of the magnetic foil is 4 mg/cm2 and it can provide 0.16 mN/mg. By programming the foils into different geometries, these soft robots are readily used for different applications, such as quick gripper that can pick, transport and release objects in a controllable manner.

[1] D. Rus et al., Nature 521, 467 (2015)
[2] M. Sitti et al., Adv. Mater. 29, 13 (2017)
[3] S. Kwon et al., Nature materials 10, 747 (2011)
[4] S.H Peng et al., J. Am. Chem. Soc. 138, 225 (2016)
[5] M. Takata et al., Nature Materials 14, 1002 (2015)
[6] J. D. W. Madden et al., Materials Today, 10, 30 (2007)
[7] J.Y. Yuan et al., Nature communications 5 (2014).
[8] G. M. Whitesides et al., Science, 337, 828 (2012)
[9] O. Sandre et al., Chem. Soc. Rev., 42, 7099 (2013).
[10] R. V. Ramanujan et al., Adv Mater., 24, 4041-54 (2012).
[11] H. Z. Liu. et al., ACS Appl. Mater. Interfaces, 8, 14182 (2016)
[12] M. Sitti et al., Nature Communications 5, 3124 (2014)
[13] D. Fragouli et al., ACS Appl. Mater. Interfaces 7, 19112 (2015).

Keywords: soft robot; magnetic field; human-mimic motion; ultra-fast actuation; super durable

Related publications

  • Lecture (Conference)
    2017 MRS Fall Meeting, 26.11.-01.12.2017, Boston, USA

Permalink: https://www.hzdr.de/publications/Publ-26759
Publ.-Id: 26759