Hello, Thank you for watching this presentation.
The title of this research is Designing Metamaterial Cells to Enrich Thermoforming
3D Printed Object for Post-Print Modification. My name is Donghyeon Ko, and my coauthors are
Jeebin Yim, Yujin Lee, Jaehoon Pyun , and our adviser professor is Woohun Lee from KAIST.
A typical 3D printed object is rigid,
It is hard to modify the object after it is printed.
Thermoforming is a possible solution to modify the printed object.
As heating makes the printed objects soft,
smoothing the objects’ surface or even bending the object becomes possible.
However, thermoforming is also limited.
Due to its low thermal conductivity, deeply and locally heating the printed object is impossible.
In this research, we aim to relieve this issue of thermoforming to facilitate post-print deformation.
Here, we introduce a possible approach.
Embedding structure with high heat transference into target region for the modification.
After heating the cells which are embedded into the printed object,
it is even possible to deform the thicker parts of the printed object.
Under this approach, our primary contributions can be summarized as follows:
First, we designed TF-Cells and compound cells for enriching thermoforming.
Second, we characterized TF-Cells to provide useful guidelines.
Third, we investigated applicable thermoforming space and implemented the examples.
Our research is positioned among studies of the hands-on approach to digital fabrication,
embedding functional structure into 3D prints, and shape-changing through heating.
Especially, we aimed to enable post-print physical deformation using single material printing.
Next, the specific structure called TF-Cells was designed
to increase heat transference when embedded into 3D prints.
Finally, our research targeted user-actuated shape-changing
Prior to designing a structure, we chose hot air from a heat gun as a heat source.
The designed structure is called Thermoformable Cells (TF-Cells),
and TF-Cells have high heat transference in universal directions.
As TF-Cells are built of beam arrays, it is applicable to most 3D geometries.
As you can see in this CFD simulation, the perforated structure shows
much higher heat transference compared to the other (non-perforated structure, Solid).
We started the cell design from a 2D array to 3D arrays.
Based on the design workshop, we derived a possible thermoforming design space.
As TF-Cells can be specifically and deeply heated,
modifying surface in-depth and even modifying form factor become possible.
As an example, we embedded TF-Cells and used stamping to copy the flower pattern (a).
Next, we embedded TF-Cells to make the printed object fit into a pipe (b) or
embed a bolt into a printed object (c).
TF-Cells enable modifying the form factor.
Four shape deformations (Stretching, Pressing, Bending, and Twisting) are possible which are shown in this video.
Focusing on PCL filament with low melting temperature,
a series of technical evaluations were conducted to provide useful guidelines for using TF-Cells.
Let me briefly introduce the results and please refer to details in the paper.
Compared to non-TF-Cells, TF-Cells showed much higher heat transference
which increases as the gap of TF-Cells increases.
Heating conditions such as heating orientation,
temperature, and airspeed affect thermoformability.
When TF-Cells are combined with Solid(Infill 100%) geometry,
it is possible to make behavior-specific cells called compound cells
which relieve issues of using TF-Cells.
We presented four compound cells which are Simple Beam, Helix, Vertical Array, and Horizontal Array.
We presented a simple tool for embedding TF-Cells.
There are three steps: specify model and target region,
specify TF-Cells, and embed the structures.
TF-Cells are representatively applicable under three contexts
which are mechanical fitting, ergonomic fitting, and aesthetic tuning.
Under mechanical fitting, we designed a three-way joint.
TF-Cells are embedded into the inlet and the neck(of the joint).
Under ergonomic fitting, we designed a screw gripper.
For assembly, TF-Cells are embedded into combining regions.
For the ergonomic fitting, we embedded two helices and one horizontal array.
Finally, we could get a well-fitted gripper.
Under aesthetic tuning, we printed a flat hand.
The structures are embedded into fingers and wrist and thermoformed into a peace gesture.
Finally, we could easily get an organic shape with simple modeling.
We believe that this approach could invite a hands-on approach
in digital fabrication from design to customization.
For any questions or collaboration please contact this email address.
Thank you for listening.