Journal of Materials Science

, Volume 54, Issue 5, pp 4444–4456 | Cite as

Particle-reinforced and functionalized hydrogels for SpineMan, a soft robotics application

  • Tobias Preller
  • Gundula Runge
  • Sabrina Zellmer
  • Dirk Menzel
  • Saeid Azimi Saein
  • Jan Peters
  • Annika Raatz
  • Brigitte Tiersch
  • Joachim Koetz
  • Georg GarnweitnerEmail author


SpineMan is designed as a prototype of a soft robotic manipulator that is constructed of alternating hard and soft segments similar to the human spine. Implementing such soft segments allows to surpass the rigidity of conventional robots and ensures safer workspaces where humans and machines can work side by side with less stringent safety restrictions. Therefore, we used a hydrogel as viscoelastic material consisting of poly(vinyl alcohol) and borax. The mechanical properties of the hydrogel were tailored by embedding silica particles of various particles sizes as well as in different mass fractions. Increased mass contents as well as larger particle sizes led to strongly enhanced rigidity with a more than doubled storage modulus of the composite compared to the pure hydrogel. Furthermore, specific functionalities were induced by the incorporation of superparamagnetic Fe3O4 nanoparticles that can in principle be used for sensing robotic motion and detecting malfunctions. Therefore, we precisely adjusted the saturation magnetization of the soft segments using defined mass contents of the nanoparticles. To ensure long-time shape stability and prevention of atmospheric influences on the prepared composites, a silicone skin of specific shore hardness was used. The composites and the soft segments were characterized by oscillation measurements, cryo-SEM, bending tests and SQUID measurements, which give insights into the properties in the passive and in the moving state of SpineMan. The utilization of tailored composites led to highly flexible, reinforced and functional soft segments, which ensure stability, easy movability by springs of the shape memory alloy nitinol and prevention of total failure.



We thank Bilal Temel for the TEM image and the Laboratory of Nano and Quantum Engineering (LNQE), Leibniz Universität Hannover, for the TEM instrument as well as Daniel Gurka for the illustrations of SpineMan.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

10853_2018_3106_MOESM1_ESM.docx (55.6 mb)
Supplementary material 1 (DOCX 56955 kb)


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© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Institute for Particle TechnologyTechnische Universität BraunschweigBraunschweigGermany
  2. 2.Institute of Assembly TechnologyLeibniz Universität HannoverGarbsenGermany
  3. 3.Institute for Condensed Matter PhysicsTechnische Universität BraunschweigBraunschweigGermany
  4. 4.Institute of ChemistryUniversität PotsdamPotsdamGermany
  5. 5.Laboratory for Emerging Nanometrology (LENA)Technische Universität BraunschweigBraunschweigGermany

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