Learning Biology Through 3D Printing

Learning Objectives • Introduce 3D printing operation theory • Show how 2 distinct types of CAD software

(parametric and mesh modeling) can be adapted to 3D printing applications

• Engage in an Anatomy bone labeling exercise

• Reveal difficulties that our grant faced when initiating this 3D printing curricula

• Summarize resources available to instructors

National Science Foundation Advanced Technological Education MODEL 3D Modeling Original Didactic Experiences in Learning 3D • Website 3d.waketech.edu • Twitter @waketech3D • Instagram @waketech3D • Email [email protected]

mailto:[email protected]

http://3dprintingindustry.com/3d-printing-basics-free-beginners-guide/technology/

What is 3D Printing? • The translation of digital

information into a physical object.

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• Insert introductory video

What is 3D Printing?

Operation Theory

• 3D printing is also known as additive manufacturing and rapid prototyping.

• 3D printers build objects by adding material layer by layer.

• 3D printers differ from traditional CNC machines that subtract a substance from a starting block of raw material.

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Additive

https://thecynicalchef.files.wordpress.com/2008/11/pancakes-047.jpg

Subtractive

http://cdn6.bigcommerce.com/s-lz5sf2/product_images/uploaded_images/what-is-whittling-knife.jpg?t=1455310108

Overview of 3D Printing • There are 3 common 3D printing techniques:

1) Binder Jet Printing (powder particles are bound or fused together)

2) Stereolithography (liquid resin is hardened by a laser beam or light)

3) Fused Filament Fabrication (plastic filament string is melted and deposited)

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Fused Filament Fabrication

• A spool of filament (typically plastic) is fed into a hot metal tip.

• Computer controls direct the hot metal tip to extrude and deposit melted filament onto a print bed.

• Additional melted filament is deposited and adheres to the preceding layers and an object is formed layer by layer.

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3D Printing is Nothing Special

• Making plastic widgets via Fused Filament Fabrication is very similar to making plastic widgets with plastic injection molding.

http://2.wlimg.com/product_images/bc-full/dir_35/1047127/injection-plastic-molding-763014.gif

Injection Molding

Creating Filament on Spool

Loading Filament from Spool

Nothing New… • Binder Jet RF Housholder

1979. Commercialized by Dr. Carl Deckard & Dr. Joseph Beaman in the 1980’s.

• STL Alain Le Mehaute 1986. Chuck Hull commercialized it in 1986.

• FFF Scott Crump invented in 1988.

http://3dprintingforbeginners.com/wp-content/uploads/2015/10/Femur-printed-on-Makerbot-Replicator-2.png

http://aptgadget.com/wp-content/uploads/2015/08/TRUMPF_DepositionLine.jpg

http://www.xconomy.com/wordpress/wp-content/images/2015/08/Carbon3D-Printer.jpg

Why All the Recent Attention?

• 2 companies, Stratasys and 3D Systems, bought 3 patents for 3D printing techniques.

• Patents began to expire in 2014 (25 years after creation).

• Reprap and open source improvement of printers

• “Maker” movement utilizes open source technology & inexpensive microcontrollers like Arduinos & Raspberry Pi to spur innovation.

https://upload.wikimedia.org/wikipedia/en/8/8c/3D_Systems_Logo_-_from_Commons.gif

https://www.3printr.com/file/2015/10/Stratasys-3.png

http://www.sloma.org/images/makers2014.png

3D Printer Uses

• Custom/ Promotional Materials

• Fashion

• Medical

• Art

• Impossible geometries http://www.slashgear.com/nefertiti-bust-secretly-scanned-3d-model-released-to-public-24428989/

Considerations for 3D Printing Objects

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http://3dprintingindustry.com/3d-printing-basics-free-beginners-guide/technology/

Orientation vs Grain

• Orientation vs grain animation-done • Overhangs animation-done

Overhang

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Generating 3D File Information

Mesh Becomes Sliced Layers

Layer Height

Infill Percentage

No Supports

With Supports

Infill and Layer Height

http://www.quora.com/Why-do-3d-printers-use-a-honeycomb-structure-to-print-out-objects http://blog.teambudmen.com/2013/09/understanding-shells-layer-height-and.html

http://enablingthefuture.org/2014/11/13/tech-talk-thursday-intro-to-3d-printing/

Why Do you want a 3D Printer?

-Is your end goal to create a usable product? -Will it mostly be used for rapid prototyping? -What sort of detail will you need? -What material fits your needs? Is the material cost effective? -What size objects will you produce?

Printer Specifications to Consider

http://www.protoparadigm.com/news-updates/tag/printer_theory

Grant Courses Cross Divisions Technical (students design printed part)

Non-technical (part is printed as learning tool)

ASSOC. ENGINEER. TECH. -EGR 285 (capstone) - DFT 154 Intro to Solid Modeling -TDP 110 Intro 3D Printing COLLEGE TRANSFER -DFT 170 Engineering Graphics (Solidworks) -MAT 273 Calculus III -PHY 251 Physics 1 -BIO 111 Biology I -BIO 168 Anatomy & Physiology I

1) Strengthen Curriculum

2) Improve Student Learning Performance & Industry Skill Acquisition

3) Collaborate with Industry & Educational Partners

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Goals and Courses

BIO 111 BIO 168

DFT 170

PHY 251

EGR 285 TDP 110 DFT 154

MAT 273

Presenter

Presentation Notes

Here’s a list of the courses that we work with on our grant. BIO 111 and BIO 168 courses are intended for students without CADD drafting, engineering, or 3D modeling experience. In BIO 111 Principles of Biology their 3D printed project is to find and 3D print proteins illustrating their different folded configurations and where the active/inactive sites are on the model. That is a 3D printed model from HIV’s Nef-1 Protein. Since adding a 3D printing project is intended to create a deeper understanding of the topic the stdents create a scientific report detailing properties of their protein and how environmental conditions would modify it’s behavior. BIO 168 is anatomy and physiology and it’s pretty easy to see how having a tangible model would benefit students by giving them a different pathway to understanding of body mechanics. DFT 170-was an easy course to augment students since students are already drafting and 3D modeling a 3 dimensional puzzle on the computer. This project allows them to then 3D print their completed work. It also is more intensive use of the 3D printers since additive manufacturing technology is a skill they will need to be competitive in finding a job and will likely use some variation of this technology in a future industry. EGR 285 is the major final course in the engineering program. These students design model and 3D print an original work as a team. This past spring semester the project was to design a cup holder for their vehicles. You can see the several variations either plugging into a cigarette lighter or clipping onto a window or mounting o a horizontal surface on their vehicle. PHY 251 General Physics 1 is an upper level class that teaches about complex equations that may not be easy to visualize in a student’s mind’s eye. Being able to convert a 3D computer generated model into a 3D printed object helps vizualization of the concept and being able to see how the machine would print the model layer by layer grounds the lesson and application of the 3D model in the real world. Lastly is TDP 110 Introduction to 3D printing. We’ve had so much interest in the grant we wanted to go more in depth into this technology and offer different perspectives and the chance for more mastery than just a passing competence with operating the machines. It will allow students to use the several differt types of equipment that we offer and more varied 3D printing projects and advanced manufacturing approaches.

Creating 3D Printed Learning Tools

• The proposed 3D printed objects for our non-technical courses, Calculus and Physics, could either be found in a CAD library online

• OR parametrically modeled by students in our drafting classes

Traditional 3D MODEL CAD Libraries • Makerbot’s Thingiverse • AUTODESK 3D Model Library • GrabCAD • Shapeways • SketchFAB • SketchUp 3D WAREHOUSE • Turbosquid • Yeggi

http://www.123dapp.com/3d-model-library

http://www.123dapp.com/3d-model-library

https://grabcad.com/

http://www.shapeways.com/

https://sketchfab.com/

https://3dwarehouse.sketchup.com/index.html

http://www.turbosquid.com/?gclid=Cj0KEQjw4ZOwBRDoxpjAvPXAl5MBEiQAEek_3n4ZZ3Y8ib98tGZFBwfyuwtgnTtev26Dh9xv98qcrB4aAgNC8P8HAQ

http://www.yeggi.com/

BIO 168 Project Parameters • Idea: reproduce plastic anatomy models • 3D printed models would complement existing

learning tools: computer 3D model viewer, bone models in the classroom, & textbooks • Students are tested on real bones in class so

there was a digital to tactile disconnect

Labeling Activity • Areas students consistently

struggled: 1) saggital (cross-section) view of skull 2) hand bones 3) feet bones • You’ll find our 3D printed labeling

activity and paint pens at your seats • Share and use the same color with

different patterns for several bones

Label Foot Bones

Label Hand Bones

Issues With printing Anatomy Bones • Non-technical class so we looked for anatomy

models in online libraries • Models requested by instructors either didn’t exist,

were too detailed or were not detailed enough

Finding Medical Quality 3D Scans

• Thingiverse http://www.thingiverse.com/

• Embodi3D http://www.embodi3d.com/

• NIH 3D Print Exchange http://3dprint.nih.gov/

• Morphosource http://morphosource.org/

http://www.thingiverse.com/

http://www.embodi3d.com/

http://3dprint.nih.gov/

http://morphosource.org/

Why No Free Models Online? • New technology (low cost 3D printers are only a few years old) • Animation and medical modeling is very time intensive skilled

work. Modelers don’t want to give away their work for free • There are CAD files for creating the plastic molds (negatives)

for models you can buy from traditional companies • Once the file is shared online, there’s no going back

Parametric Modeling vs Mesh Modeling

• 3D printers work best for items that are designed in a parametric 3D modeling program

• I.e. Solidworks, AutoCAD, SketchUp, Inventor, Fusion360 etc.

• The designer chooses the shape, angle, dimensions, and thickness of the object

• 3D printers handle parametric models well because human design is typically based on simple geometry at the human scale

• 3D printers translate printed information on an X, Y, Z coordinate plane system

• Mesh models represent organic shapes more accurately but are hander to physically realize

Parametric Modeling vs Mesh Modeling

Generating Mesh File Data • Since Mesh is just connected polygons (triangles

or “T” splines) there are no guiding parameters • Mesh model detail depends on quality of scanner • Higher quality scanner=more polygons in mesh

Mesh Models were Too Detailed • 3D Medical scanners, like MRI and CT machines

scan everything: bumps, holes, imperfections, even marrow inside of the bones.

• We just need a representative model of the exterior “shell”

Necessary Model Specifics • Bones must be connected to each other • Need to still show the detail of the bon edges to see

how and where they connect Thingiverse Trial 30% scale model Final Morphosource 100% scale model

A Note On Tools

• Fusion360

• Meshmixer

• Zbrush

• Avizo

• Materialise

Learning Limitations of Our 3D Printers

• Bowden tube vs direct drive mechanisms • Our F306 3D printers have a long Bowden

tube and experience a great amount of retraction

Direct Drive Feed

Starting to Get Success • Printed on Makerbot’s direct drive (no Bowden tube) • Printed a prepared & hollowed out anatomy file • Filament supplier was a new company with bad

manufacturing quality control • Sent it back because of inconsistent diameter

http://www.protoparadigm.com/news-updates/filament-tolerances-and-print-quality/

Irregular Filament

http://www.protoparadigm.com/news-updates/filament-tolerances-and-print-quality/

Temperature change

Ambient Moisture

Physical Damage

In 12 months filament degrades due to UV exposure and moisture

absorption and becomes unusable

Environmental Influences on Print

More Printer Limitations • Makerbot’s axes are driven by stiff rubber belts

not kevlar string • Belts can only move linearly • Wrapped kevlar stretches and moves out of line


Future Projects • Help from Duke’s Evolutionary Anthropology

Department • Free used funds for MicroCT machine • Can clean up models with professional quality

medical modeling software

Printing Considerations

• Finding high quality detailed files • Bones that were connected • Hollowed out interior and simplified exterior • Type of printer (bowden vs direct drive) • Axes controlled by kevlar vs rubber belt • Filament quality • Deleted unnecessary extra information (carpals

and tarsals) to save time, filament and complexity

Recap of Resources:

Recap of Resources

• Website 3d.waketech.edu • Twitter @waketech3D • Instagram @waketech3D • Email [email protected]

mailto:[email protected]

Any Questions?

http://3.bp.blogspot.com/-1Qy5JYgfmaE/UvGmUMo_Z_I/AAAAAAAABgc/Ap3KfCpFjso/s1600/DSC_0287.JPG

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Learning Biology Through 3D Printing