università di pavia · caratterizzazione biomeccanica dei materiali 3d printing and biomechanics...
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Pag. 2
La stampa 3D per Impresa 4.0
3D PLAST e PLAST 2018
30 Maggio 2018
Ferdinando Auricchio
Dip. Ingegneria Civile e Architettura
Università di Pavia
Prof. Ferdinando AuricchioComputational Mechanics and Advanced Material Group
University of Pavia
Milan, June 2018
3D Printing @ UniPV
RILEM – 25/05/18, Naples
Combining Additive Manufacturing with virtual modeling and advanced materials,
through 5 PILLARS
Modeling &
Simulation
ManufacturingSocio-Eco
Impact
Applications
New
Materials
3D printing as strategic University activity
Patient-specific Anatomical Models
A new instrument for surgical planning and simulation
MDTC Scan Image Segmentation 3D Virtual Model
Minimally Invasive RoboticSurgery
Surgical Planning, Simulation& Training
3D Printed Model
Patient-specific Anatomical Models
Models for spleen laparoscopic resectionand splenic artery aneurysm esclusion.
Deformable
materials
Used to simulate the
surgery
Left heart cavity reconstruction.
The model has been used to plan surgical access from
pulmonary arteries to the point of interest.
Temporal bones thickness map and ear/scalpreconstruction to be used for surgical planning and access
evaluation.
• Red high thickness• Green medium thickness• Blue low thickness
Patient-specific Anatomical Models
Our 3D printed models are intended for all medical specialities. Todate, we have several years of experience in the areas of:
Medical Field #Cases
Abdominal Surgery(Prof. A. Pietrabissa)
> 45
Otolaryngology & Maxillofacial
Surgery(Prof. M. Benazzo, Prof. P. Canzi)
> 15
Orthopedics(Prof. F. Benazzo)
> 15
Vascular Surgery(Prof. E.M. Marone, Prof. S. Trimarchi, Prof. P. Quaretti)
> 35
Total 118
Produce a copolymeric PLA-PCL patch for esophageal tissue regeneration
Thermoplastic biocompatible
polymers
PCL (polycaprolactone)
PLA (polylactic acid)
Setting of printing parameters and 3D
printing
Final esophageal patches
Biological analysis and mechanical characterization
In collaboration with: Prof. Bice Conti & Drug Science Department
Biocompatible materials for implantable scaffolds and 3D printing
Regenerative Medicine
3D networks made of biocompatible
thermoplastic polymers
Hydrogels Cells Bioink Bioprinting
Biological components (cells) are encapsulated in
hydrogels
Used in biomedical and tissue engineering
applications
Layer by layer deposition of bioink
Bioprinting
Cellink Start: soluble support material(CellInk patented)
6%Sodium-Alginate + 4%Gelatin + 0,4%CalciumChloride
3D printing process allows tuning the dielectric characteristics of substrate materials.
Different printing patterns and infill densities canbe adopted.
E. Massoni, L. Silvestri, M. Bozzi, L. Perregrini, G. Alaimo, S. Marconi, and F. Auricchio, "Characterization of 3D-Printed Dielectric Substrates with Different Infill forMicrowave Applications," IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP 2016),
Chengdu, China, July 20-22, 2016.
Milan, June 2018
Samples printed by using TPU filament (Ninjaflex ®).
Dielectric properties’ tuning
Micro-wave applications
Milan, June 2018
The use of a gypsum powder (binder jetting machines) can significantly reducedielectric loss with respect to Ninjaflex®
Reduced Losses
The material is used to design a Non Radiative Dielectric (NDR)-guide
Gypsum powder design
Ninjaflex® design
Dielectric properties’ tuning
Reinforced Materials
Material reinforcement Strength-weight ratio
Mechanical properties
Higher costs
Example:
• Matrix: Poly-Lactic Acid (PLA)
• Reinforcement: Graphene
NanoPlatelets (GNPs)
GoalInvestigate the impact of GNPs addition in different percentages on mechanical properties
• 1.75mm filament reinforced with:
o 0% GNPs = base PLA material
o 1% GNPs by weight
o 2% GNPs by weight
• One specimen printed at a time
o Tensile test samples
o Extruded at 200ºC
o Printing bed at 55ºC
• At the end of the printing
o Each specimen is left cooling down to RT
• Three different fiber orientations
o 0° fibers characterization
o 90° fibers’ bonding characterization
o 45° in-plane shear behavior
• Mechanical characterization features :
o Geometry: ASTM D3039 (composite materials)
o Unidirectional specimens
o No perimeters
Milan, June 2018
Reinforced Materials
Strain at break [mm/mm]Stress at break [MPa]
[MP
a]
[MP
a]
Milan, June 2018
In conclusion:
GNPs cause
• Brittle failure of the material
• More visible at 90°
• Due to the thermal conductivity increase
GNPs improve
• The shear stiffness
• Thermal operational range
• Fine details printing, thanks to the fast cooling
Elastic Modulus [MPa]
Structural problem
Allowing pointwise fiber
orientation it is possible to
dramatically improve structural
response
What is the best material
orientation that maximize the
total load q ?
Optimized solution
Optimization of structural problems
Numerical results
• Pointwise optimization: +107% in terms of maximum
load q
• Pointwise optimization: consistent reduction of the
global yielding
Piecewise - uniform 3D printed component
Optimization of structural problems
Advanced ceramic low-cost 3D printing
Goal) Design specific processes based on low-cost FDM 3D printing to synthesize advanced ceramic components with a complex shape
3. The polymer is then removed by
thermal degradation
4. Full densification is obtained by
sintering
Expected result) 3D printing of Ceramic Carbides and Cemented Carbides (SiC,TiC,WC,Co-TiC, Co-WC)
2. The 3D printing is realized with standard (low-
cost) FDM machines
1. A precursor wire is designed to have
appropriate proportions of polymer and
inorganic powders
Preliminary results:
Robocasting represents a low-cost
approach for 3D printing ceramic oxides
Expected result)Obtain bulk and complex shaped metal (or metal-caramic) composites through robocasting
Metal low-cost 3D printing
Goal) Design specific processes based on low-cost viscous liquid extrusion (VLE) to synthesize metal components with a complex shape exploiting oxide reduction
“INK” preparation 3D printing (VLE) Thermal treatments
A carefully optimized thermal treatment allows
shape retaining of the printed objects
Metal printing via oxide reduction
The process can be extended to the printing of
metal-ceramic composites
Printable Materials:
•Cu, Ni, Co and their alloys
•ZrO2, Al2O3, TiO2
•TiC, SiC (reactive sintering)
CuO Cu
www.unipv.it/compmech/idbn_home.html
Università di Pavia, 5-7 Settembre 2018
ESB-ITA
Segreteria AmministrativaDip. I ng. Civile e Architettura – DI CAr
Via Ferrata, 3 – 27100 Pavia (I talia)
Laura Mazzocchi -Tel. 0382 985475,
Anna Painelli -Tel. 0382 985301,
Organizzatori:
Ferdinando Auricchio
Michele ContiStefania Marconi
Ampia Area Espositiva Presentazione Biomodelli
I ntegrazione tra le varie discipline mediche
e le più moderne tecnologie di stampa 3D
Digital Biomanufacturing & Clinical Impact
Personalizzazione della diagnosi e del t rattamento:
dall’imaging medico al modello stampato.
Progettazione, Simulazione,Caratterizzazione biomeccanica dei materiali
3D Printing and Biomechanics
2° Congresso IDBN - I talian Digital Biomanufacturing Network
I I I Thematic ConferenceEuropean Society of Biomechanichs-ITA
Sottomissione contributiEntro 1 Giugno
Comunicazione accettazioni15 Giugno
Pag. 19
La stampa 3D per Impresa 4.0
3D PLAST e PLAST 2018
30 Maggio 2018
La stampa 3D per Impresa 4.0In 3D PLAST e PLAST 2018