Origami-inspired Design of a Deployable and Collapsible Spherical

Origami-inspired Design of a Deployable and Collapsible Spherical Device Intended for Ablation Therapy
Michelle Cho, Hope Lee, Jinda Zhuang, Professor Y. Sungtaek Ju
Department of Mechanical and Aerospace Engineering, University of California – Los Angeles
\
Space-saving instruments can facilitate certain sensitive procedures
Parts are modified several times to fit original requirements
Objective: To design a deployable structure that would aid in minimally-invasive operations,
particularly ablation therapy, resulting in less bleeding, shorter recovery time, and smaller incision
size for the patient
First Approach:
Expandable and
Collapsible Folded
Petal Structure
Ablation therapy: A procedure involving the removal of
abnormal tissues that surface due to certain conditions
http://www.nature.com/nrcardio/journal/v10/n2/full/nrcardio.2012.198.html
Approach process mapped for designing and creating structure
Requirements:
•  Easily expandable using balloon inflation
•  Self-collapsible
•  Smooth surface
Design
Requirements
Scale Down
Original Origami
Magic Ball and
Petal Structure
Create
Prototype
Second Approach:
Structure with
Alternation between
Magic Ball Model
and Folded Petals
• Strips of the Magic Ball were used along with
measured petals, which were folded with an
alternation of mountain and valley folds
• Flaws: Petals separated from each other even
though overall structure was connected; the entire
surface was not smooth
Final Approach:
Overlapping Petal
Surface Over a
Complete Magic
Ball Structure
• Measured, overlapping petals used to cover a
Magic Ball in collapsed form
• Petals calculated to expand along with the Magic
Ball in order to form the smooth surface of a
sphere
• Meets requirements
Fail
Modify
Structures
Test
Design
Succeed
Efficiency of designs measured by material usage, volume, and surface area
Design
Magic Ball and petals appropriate for an origami-inspired model
Origami Expansion: Origami expansion has recently started being used to create more flexible
First Approach
Second Approach
Final Approach (Prototype)
Volume (cubic inches)
devices, including solar panels and robots. Engineers mostly focus on different types of
tessellation folds, such as the Miura folding pattern, because of their great levels of flexibility and
their rigid quality, meaning they include only straight creases and flat planes.
The original inspiration of design
was the Magic Ball, a Miura
folding structure. This model
was used to provide the basic
structure for the final design.
http://how-to-make-origami-magic-ball.blogspot.com/
Replication of Spherical Surface with Petals:
Demaine et al. "Wrapping Spheres with Flat Paper." Computational Geometry 42.8 (2009): 748-57. Web.)
30
171.64
318.08
636.16
Surface Area Compression
Volumetric Expansion
25
20
15
10
5
0
Although the final design meets
all the requirements, it requires
the largest amount of material.
Cylinder
Structure
Sphere
350 350
300 300
250 250
200 200
150 150
100 100
5050 0 0 Paper Paper
Sphere Sphere
Structure
Cylinder Cylinder
Volumetric Expansion: 109.05% from cylinder to sphere
Surface Area Compression: 171.74% from paper to sphere, 201.05% from cylinder to sphere,
742.54% from paper to cylinder
http://origamiks.com/images/stories/schems/Blog/2012week10/magic_ball.jpg
Petals were used to replicate the
smooth surface of a sphere,
where electronic probes or
components will later be placed.
Material Usage (cm squared)
Surface Area
(Square Inches)
During the operation, doctors insert catheters, or flexible
tubes, through major arteries to reach the target area.
Then, they ablate, or destroy, the tissue.
• Consisted of separate petals folded with a water
bomb base (repeating fold used in creation of
Magic Ball)
• Flaws: Petals separate from one another, unable
to incorporate electronics and difficult to expand
and collapse
Further work could prove useful for real-life applications
• 
• 
• 
• 
Scale down to desired size (around 3 cm when expanded) for use at the end of a catheter
Incorporate electronics used to ablate certain tissues
Utilize more durable materials for insertion in to the body
Minimize material usage with mathematical modeling
Acknowledgements
We would like to thank William Herrera, Dean Dhir, and the High School Summer Research Program for offering this wonderful opportunity to work in a
university laboratory setting, in addition to James Che and Harsha Kittur for their mentorship and guidance.