Multi-material 3D-Printer for Rapid
Prototyping of Bio-Inspired Soft Robotic
Elements
Stefan Conrad 1,2(B) , Thomas Speck 1,2,3 , and Falk Tauber 1,2
1 Plant Biomechanics Group (PBG) Freiburg, Botanic Garden of the University of Freiburg,
Freiburg im Breisgau, Germany
stefan.conrad@biologie.uni-freiburg.de
2 Cluster of Excellence LivMatS @ FIT – Freiburg Center for Interactive Materials
and Bioinspired Technologies, University of Freiburg, Freiburg im Breisgau, Germany
3 Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT),
University of Freiburg, Freiburg im Breisgau, Germany
Abstract. A rising trend can be observed in robot development towards the usage
of flexible materials, whose properties resemble their biological counterparts. This
way of design promises machines that are more adaptive, energy efficient and cost
effective. One of the biggest challenges in this growing research field is the fabrication of functional elements, which consist of several embedded materials. The
lack of compatible substances and of a proper prototyping technology limits the
possible complexity and the degree of automation in prototyping. Furthermore,
additive manufacturing techniques are usually designed for predefined purposes
and do not have the customizability the research in an innovative field requires. In
order to address this problem a novel multi-material 3D-printer with on-demand
tool change has been developed. The adaptive locking mechanism in combination
with a kinematic coupling allows the device to switch between tools varying in the
dispensed material and even work principle. Using specifically developed directly
driven filament-print-heads, a series of test specimen has been fabricated. The very
reliable and precise extrusion, even of highly flexible material, is demonstrated in
form of airtight chambers utilized as pneumatic actuators. In an additional demonstrator the flexible part has been reduced to a single expandable membrane as the
active element included in an otherwise stiff housing. A specific design made it
possible to embed the membrane in the surrounding, which compensated for the
lack of chemical bonding between both substances and created a pneumatic actuator with a much better stability/performance ratio. These demonstrators highlight
the great potential to create yet unbuilt biomimetic structures and multi-material
systems with this novel multi-material printer.
Keywords: Multi-material 3D-printer · PLA-TPU embedment · Pneumatic
actuators · Soft robotics · Biomimetics
© Springer Nature Switzerland AG 2020
V. Vouloutsi et al. (Eds.): Living Machines 2020, LNAI 12413, pp. 46–54, 2020.
https://doi.org/10.1007/978-3-030-64313-3_6
Prototyping of Bio-Inspired Soft Robotic
Elements
Stefan Conrad 1,2(B) , Thomas Speck 1,2,3 , and Falk Tauber 1,2
1 Plant Biomechanics Group (PBG) Freiburg, Botanic Garden of the University of Freiburg,
Freiburg im Breisgau, Germany
stefan.conrad@biologie.uni-freiburg.de
2 Cluster of Excellence LivMatS @ FIT – Freiburg Center for Interactive Materials
and Bioinspired Technologies, University of Freiburg, Freiburg im Breisgau, Germany
3 Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT),
University of Freiburg, Freiburg im Breisgau, Germany
Abstract. A rising trend can be observed in robot development towards the usage
of flexible materials, whose properties resemble their biological counterparts. This
way of design promises machines that are more adaptive, energy efficient and cost
effective. One of the biggest challenges in this growing research field is the fabrication of functional elements, which consist of several embedded materials. The
lack of compatible substances and of a proper prototyping technology limits the
possible complexity and the degree of automation in prototyping. Furthermore,
additive manufacturing techniques are usually designed for predefined purposes
and do not have the customizability the research in an innovative field requires. In
order to address this problem a novel multi-material 3D-printer with on-demand
tool change has been developed. The adaptive locking mechanism in combination
with a kinematic coupling allows the device to switch between tools varying in the
dispensed material and even work principle. Using specifically developed directly
driven filament-print-heads, a series of test specimen has been fabricated. The very
reliable and precise extrusion, even of highly flexible material, is demonstrated in
form of airtight chambers utilized as pneumatic actuators. In an additional demonstrator the flexible part has been reduced to a single expandable membrane as the
active element included in an otherwise stiff housing. A specific design made it
possible to embed the membrane in the surrounding, which compensated for the
lack of chemical bonding between both substances and created a pneumatic actuator with a much better stability/performance ratio. These demonstrators highlight
the great potential to create yet unbuilt biomimetic structures and multi-material
systems with this novel multi-material printer.
Keywords: Multi-material 3D-printer · PLA-TPU embedment · Pneumatic
actuators · Soft robotics · Biomimetics
© Springer Nature Switzerland AG 2020
V. Vouloutsi et al. (Eds.): Living Machines 2020, LNAI 12413, pp. 46–54, 2020.
https://doi.org/10.1007/978-3-030-64313-3_6