Programming Material Intelligence
43
actuators. The physical material and fabrication logic, rather than any electronics or digital control, dictate the self-shaping behaviors. We formulated a
method for designing and 3D-printing material properties, such as elasticity and
compliance of varying magnitudes and anisotropies, using functional patterns.
We also detailed the tectonic interface between natural and synthetic parts of
the hybrid system. Finally, we established a strategy for producing macro-scale
biohybrid components through a sequential process of multi-material additive
fabrication.
3.1 Discussion
While our results indicate the potential of leveraging natural wood actuators
with 3D-printing, our current approach still has a number of limitations and
open questions. The wood bilayer actuators, when embedded in the biohybrid
components, must overcome the inherent resistance caused by its 3D-printed
armature. This can generally be mitigated by 3D-printing with thermoplastic
elastomers. Starting with a lower baseline elastic modulus allows the range of
tunable material properties to be expanded, as stiffness is more easily increased
through added height and density in the functional patterns. Moreover, thicker
wood bilayers could be employed for their higher actuation forces. For further
upscaling, it will be important to consider the resultant increase in the structure’s
self-weight, especially during the self-erecting process. This might be alleviated
by the strategic distribution of wood bilayer actuators in the system, coupled
with 3D-printed functional patterns that optimize the ratio between strength to
weight.
3.2 Outlook and Future Work
Biohybrid parts which move in response to the changing weather without electrical power can potentially serve as a solution to energy-efficient indoor climate
control [10]. Although we have shown self-shaping at a range of spatial scales, the
adoption of biohybrid components in buildings will require further exploration
of the additional functionalities which are enabled by this material programming
and additive fabrication approach. For the application of responsive facades that
can manage the indoor climate, it will be necessary to overcome the poroelastic
time scale. In the case of irreversible self-shaping such as in deployable structures
and shells, safety mechanisms for locking the desired shape change will need to
be investigated. Beyond the use of wood, other combinations of natural material
actuators and synthetic material programming could be particularly interesting
for large-scale self-shaping systems.
Acknowledgements. The research was partially supported by the Sino-German Centre for Research Promotion – GZ 1162 – and the German Research Foundation DFG
under Germany’s Excellence Strategy – EXC 2120/1 – 390831618. Additionally, this
work was tested in a workshop setting at the Digital Futures 2018 conference in Shanghai. The authors especially thank Long Nguyen and Ahmad Razavi for their help in
43
actuators. The physical material and fabrication logic, rather than any electronics or digital control, dictate the self-shaping behaviors. We formulated a
method for designing and 3D-printing material properties, such as elasticity and
compliance of varying magnitudes and anisotropies, using functional patterns.
We also detailed the tectonic interface between natural and synthetic parts of
the hybrid system. Finally, we established a strategy for producing macro-scale
biohybrid components through a sequential process of multi-material additive
fabrication.
3.1 Discussion
While our results indicate the potential of leveraging natural wood actuators
with 3D-printing, our current approach still has a number of limitations and
open questions. The wood bilayer actuators, when embedded in the biohybrid
components, must overcome the inherent resistance caused by its 3D-printed
armature. This can generally be mitigated by 3D-printing with thermoplastic
elastomers. Starting with a lower baseline elastic modulus allows the range of
tunable material properties to be expanded, as stiffness is more easily increased
through added height and density in the functional patterns. Moreover, thicker
wood bilayers could be employed for their higher actuation forces. For further
upscaling, it will be important to consider the resultant increase in the structure’s
self-weight, especially during the self-erecting process. This might be alleviated
by the strategic distribution of wood bilayer actuators in the system, coupled
with 3D-printed functional patterns that optimize the ratio between strength to
weight.
3.2 Outlook and Future Work
Biohybrid parts which move in response to the changing weather without electrical power can potentially serve as a solution to energy-efficient indoor climate
control [10]. Although we have shown self-shaping at a range of spatial scales, the
adoption of biohybrid components in buildings will require further exploration
of the additional functionalities which are enabled by this material programming
and additive fabrication approach. For the application of responsive facades that
can manage the indoor climate, it will be necessary to overcome the poroelastic
time scale. In the case of irreversible self-shaping such as in deployable structures
and shells, safety mechanisms for locking the desired shape change will need to
be investigated. Beyond the use of wood, other combinations of natural material
actuators and synthetic material programming could be particularly interesting
for large-scale self-shaping systems.
Acknowledgements. The research was partially supported by the Sino-German Centre for Research Promotion – GZ 1162 – and the German Research Foundation DFG
under Germany’s Excellence Strategy – EXC 2120/1 – 390831618. Additionally, this
work was tested in a workshop setting at the Digital Futures 2018 conference in Shanghai. The authors especially thank Long Nguyen and Ahmad Razavi for their help in