Programming Material Intelligence
39
Materials and Methods for Evaluation. To understand how the functional
patterns cause bending and stretching, tests were conducted using thermoplastic copolyester filament (FlexiFil, FormFutura, Nijmegen, Netherlands) with a
0.5 mm extruded width. Physical coupons with dimensions of 50 mm × 50
mm × 5 mm and 50 mm × 25 mm × 5 mm were used to evaluate in-plane
stretching and out-of-plane bending, respectively. We quantified the material
properties of our physical samples by incrementally applying force with a spring
scale (Medio-Line Spring Scale 40025, Pesola, Schindellegi, Switzerland), causing
either pulling or deflection.
Analysis of Material Behavior. The amount of in-plane deformation is
impacted by the geometry of wave patterns; the frequency and amplitude of
the waves affect how much the object can stretch and compress (Fig. 1 F).
These parameters can also vary orthogonally to promote anisotropy (Fig. 1 G).
Varying the distributions between orthogonal directions will increase bending
stiffness in one direction, while promoting flexural compliance and thus out-ofplane bending in the other direction. We found that under the same pulling
force, high anisotropy in the direction of loading resists bending (Fig. 1 J) while
the opposite anisotropy facilitates bending in the same direction (Fig. 1 I). The
thickness of material distributions along each direction additionally tunes the
measure of compliance (Fig. 1 H).
2.2 Strategy for Integrating Wood Bilayer Actuators
The biohybrid components gain their self-shaping abilities through natural wood
bilayer actuators embedded within the synthetic 3D-printed armature. Although
performing discrete functions, each material is programmed to work with the
other (Fig. 2 A–C). As a wood bilayer actuator bends in one direction, its 3Dprinted armature should be flexible enough to permit unhindered bending in
that direction; the neighboring functional patterns should also be aligned to
transfer loads in the direction orthogonal to bending. From another perspective,
the wood bilayer actuator provides structural integrity in the direction where
the 3D-printed armature is weakest, while the surrounding functional patterns
enable the wood bilayer actuators to extend its area of influence. To fuse the
wood-plastic interface as a holistic entity and prevent damage due to stress
concentrations where wood meets plastic, we increase the 3D-printing flow rate
of functional patterns surrounding the wood bilayer actuator.
Materials and Methods for Evaluation. We evaluated the integration of
the natural and synthetic parts by comparing biohybrid components to a naked
wood bilayer actuator. The biohybrid samples (150 mm × 150 mm) were embedded with 150 mm × 30 mm sized wood bilayer actuators. A naked sample with a
single wood bilayer actuator of the same size acted as the control for this experiment. The wood bilayer actuators used in these experiments were constructed
out of maple veneer and calibrated to be flat at 70% relative humidity (RH).
39
Materials and Methods for Evaluation. To understand how the functional
patterns cause bending and stretching, tests were conducted using thermoplastic copolyester filament (FlexiFil, FormFutura, Nijmegen, Netherlands) with a
0.5 mm extruded width. Physical coupons with dimensions of 50 mm × 50
mm × 5 mm and 50 mm × 25 mm × 5 mm were used to evaluate in-plane
stretching and out-of-plane bending, respectively. We quantified the material
properties of our physical samples by incrementally applying force with a spring
scale (Medio-Line Spring Scale 40025, Pesola, Schindellegi, Switzerland), causing
either pulling or deflection.
Analysis of Material Behavior. The amount of in-plane deformation is
impacted by the geometry of wave patterns; the frequency and amplitude of
the waves affect how much the object can stretch and compress (Fig. 1 F).
These parameters can also vary orthogonally to promote anisotropy (Fig. 1 G).
Varying the distributions between orthogonal directions will increase bending
stiffness in one direction, while promoting flexural compliance and thus out-ofplane bending in the other direction. We found that under the same pulling
force, high anisotropy in the direction of loading resists bending (Fig. 1 J) while
the opposite anisotropy facilitates bending in the same direction (Fig. 1 I). The
thickness of material distributions along each direction additionally tunes the
measure of compliance (Fig. 1 H).
2.2 Strategy for Integrating Wood Bilayer Actuators
The biohybrid components gain their self-shaping abilities through natural wood
bilayer actuators embedded within the synthetic 3D-printed armature. Although
performing discrete functions, each material is programmed to work with the
other (Fig. 2 A–C). As a wood bilayer actuator bends in one direction, its 3Dprinted armature should be flexible enough to permit unhindered bending in
that direction; the neighboring functional patterns should also be aligned to
transfer loads in the direction orthogonal to bending. From another perspective,
the wood bilayer actuator provides structural integrity in the direction where
the 3D-printed armature is weakest, while the surrounding functional patterns
enable the wood bilayer actuators to extend its area of influence. To fuse the
wood-plastic interface as a holistic entity and prevent damage due to stress
concentrations where wood meets plastic, we increase the 3D-printing flow rate
of functional patterns surrounding the wood bilayer actuator.
Materials and Methods for Evaluation. We evaluated the integration of
the natural and synthetic parts by comparing biohybrid components to a naked
wood bilayer actuator. The biohybrid samples (150 mm × 150 mm) were embedded with 150 mm × 30 mm sized wood bilayer actuators. A naked sample with a
single wood bilayer actuator of the same size acted as the control for this experiment. The wood bilayer actuators used in these experiments were constructed
out of maple veneer and calibrated to be flat at 70% relative humidity (RH).