Supermaterials
http://beachlab.org/supermaterials
Who is this guy?
India
Sitges, Barcelona (Spain)
The Beach Lab
Mobile Fab Lab
Electronic components
Fab Foundation International Deployments
Youtube Channel The Beach Lab
Video Producer at The Fab Foundation
hola at beachlab dot org
Materials Science
Analyse existing materials. Create new compounds
meta-material
Any material engineered to have a property that is not found in naturally occurring materials.
Resonant metamaterials
If you want to find the secrets of the universe, you must think in terms of energy,
frequency and
vibration.
Nikola Tesla
Acoustic metamaterial
Metamaterial antenna
Bending Light
Mechanical metamaterials
Structural applications
Increased Damping performance
Nanotechnology
Origami
Kirigami
Structural Engineering
Sir Isaac Newton
Hooke's Law
Stress proportional to strain
Brittle Materials
We don't like that
Ductile Materials
There is a warning before failure
Ductile Materials
Elastic vs Plastic deformation
Young Modulus: E
Slope of the elastic line
Poisson Ratio
Expansion or contraction of a material in directions perpendicular to the direction of loading
Shear Modulus: G
Indenting an auxetic material is difficult
Design Software
Machines can't do anything
Laser cutter
Kerf and power
Laser cutter
Kerf and focus
Laser cutter
Focal Lenght
3D Printer
Nozzle size
Milling Machine
Vibrations
Flexures and Mechanisms
Mechanism
Degrees of Freedom
In a 3D space we have 6 DOF: 3 translations and 3 rotations
Structural supports
Supports constrain DOF
Fixed support under lateral load
Tension in external fibers and compression in internal
Fixed support under lateral load
Displacements
Fixed support under lateral load
Rotation
Fixed frame under lateral load
No rotation
Fixed frame under lateral load
Displacements
Fixed dual frame under lateral load
No rotation
Fixed dual frame under lateral load
Displacement on the direction of load
Bistability
Stable - Global buckling - Stable
Bistability
Store information in a mechanical device
Pinned supports
DOF of Pinned supports
Pinned supports
Welcome your friend the neutral fiber
Cutting joints
Test the material and the machine
Cutting joints
Rigid materials require analysis
Buckling
Global Buckling. Slender columns under compression
Beyond the elastic limit
Elastic Buckling of a structure
We want that!
Buckling matrix: rotations/counter-rotations produce auxetic behaviour
Different void shape leads to different Poisson's ratio
Critical buckling load of pinned column \[P_{cr} = \frac{\pi^2EI}{L^2}\]
Compaction Through Buckling in 2D Periodic, Soft and Porous Structures: Effect of Pore Shape. May 2, 2012. Read the full paper here
Honeycombs
Reentrant structure
Bowtie Honeycomb
Trigonometry 101
Metamaterial Honeycombs applications
Pororosity control
3D Bowtie Structure
Honeycomb Variants
Introducing flexural hinges
Honeycomb Variants
Linear vs curved links
Other reentrant Honeycombs
(a) Arrowhead (b) Lozenge grid and square grid (c) 3-STAR, 4-STAR and 6-STAR systems
Chiral Structures
Hexachiral Unit
Chiral Structures
Chiral structures based on hexagonal and re-entrant hexagonal honeycombs. (a) Trichiral honeycomb. (b) Anti-trichiral honeycomb. (c) Re-entrant trichiral honeycomb. (d) Re-entrant anti-trichiral honeycombs.
Chiral Structures
Tetrachiral Structure
Chiral Structures
3D Chiral Structure
Origami
Architecture (?)
Aerospace
Deployable Structures
Square twist
Creating creases
Single side Laser marking technique for creases
Creating creases
Single side Laser dashing technique for creases
Creating creases
Bistable square twist
Thick materials
Folding at specific angle
Thick materials
Folding 180 degrees
Product Design
Solid Gray Backpack
Offset-panel technique
Offset-panel technique
Kirigami
kiri-gami
the Japanese art or technique of cutting and folding paper into objects or designs.
Rotating (semi-) rigid structures
Squares and rectangles
Squares and rectangles
Type I and Type II rotating rectangles. Type I showing rhombi in their empty space and Type II showing parallelograms.
Squares and rectangles
Cellular plates with (1) rectangular perforations and (2) rhomboidal perforations.
Rhombi
Rotating rigid rhombi systems.
Warning!
Parallelograms
Rotating rigid parallelograms systems.
Going crazy
Programming shape using kirigami tessellations, Nature Materials 2019. Read the full paper here
Examples
Kirigami Generator
http://fab.academany.org/2018/labs/fablabulb/FAB14_workshop.htmlSimulation
FEM steps
- Load the geometry
- Obtain a mesh of tetrahedrons
- Set the material properties
- Define the type of analysis
- Define the loads or imposed movements
- Define the constrains
- Run the simulation!
Materials Properties
| Material | Density \((kg/m^3)\) | Young's Modulus \(E (GPa)\) | Poisson Ratio \(\nu\) |
|---|---|---|---|
| Acrylic | \(1180\) | \(3.2\) | \(0.36\) |
| PLA | \(1240\) | \(3.64\) | \(0.36\) |
| NinjaFlex | \(1040\) | \(0.112\) | \(0.34\) |
| Silicone Rubber | \(1700\) | \(0.025\) | \(0.48\) |
Beware units...
A.I. and Metamaterials
The Suitcase
Now What?
keywords
metamaterials, auxetics, NPR, tessellations
Thank you and stay in touch!
Supermaterials Workshop was first deployed in TechWorks Amman, Jordan. Introductory and Advanced versions taught by Fran Sanchez and TA Murad Sadeeh and Ahmed Fares in March 2021.