thermo-mechanical metamaterials: towards stimuli ...€¦ · thermo-mechanical metamaterials:...
TRANSCRIPT
Thermo-Mechanical Metamaterials: Towards
Stimuli Responsive Micro-Robotics
1
26/05/2020
Besançon, France
Q. X. Ji, J. Moughames, J.Y. Qu, C. Clevy, Rabenorosoa, V. Laude,
M. Kadic
4D Printing & Meta Materials Conference
Material A
Material B
The bilayer beam expands (shrinks) and bends upon heating (cooling) due to the
difference in thermal expansion.
This thermal-mechanical process can be used as the deformation initiator, e.g.
thermal actuators for soft micro-robots.
Deformation mechanism of a bi-material beam
2
1 Introduction
Mechanism:
A real robot arm ( Images from: https://www.google.com/search )
Controlling principle of robot arms made
on thermo-mechanical blocks
3
1 Introduction
We design metamaterial blocks that each can translate and rotate in one
axis direction by thermal-stimuli. 2
1 We build a three-axis setup to complete 3D movement.
Pick-and-place task:
Working principle
1
(b)
A single cell and its operating principle: (a) undeformed and (b) deformed.
The high (low) expansion material is depicted in red (blue).
The bi-material beam bends upon heating, resulting in overall upwards translation
of the single cell.
Translation blocks
z
x y
2(a) 1<2
0 1.4 Displacement (mm)
ΔT=40K
4
2 Thermal-mechanical design
Deformed manner of the five-layer translation lattice
The top end moves upwards by d =6.54 mm. (1=8e-5 1/K, 2=5e-5 1/K, L=50 mm,
t=1 mm).
For clarity, the deformation is up-scaled by 10 times.
0
6.6
Tra
nsla
tio
n d
isp
lace
me
nt (μ
m)
d
L
z
x y
Parameters from: Qu, SCI REP, 2016
ΔT=40K
5
2 Thermal-mechanical design
Displacements against built parameters for the built five-layer translation
lattice (ΔT=40K)
Linear relation is observed between d and L (d and Δ Δ).
In Fig.(b), we fix 1 and increase 2 to get different D
(b) (a)
6
2 Thermal-mechanical design
Simulations
We investigate the actuation force that can be used to move objects by placing a
load on top of the extended lattice.
Deformed Undeformed
0 Displacement (mm)
ΔT=40K
7
2 Thermal-mechanical design
7
Actuation force
Simulated displacement of a single translation
cell with the change of force
Geometrical nonlinearity was considered.
The amplitude d increases linearly with the number of layers.
This Photo by Unknown Author is licensed under CC BY-SA-NC
8
2 Thermal-mechanical design
d
Spring-mass model
(ΔT=40K)
( Images from: https://www.google.com/search )
x
z y
(b)
A rotation cell : (a) undeformed and (b) deformed by 20 times.
(a)
The high (low) expansion material is depicted in red (blue).
The bi-material beam bends upon heating, resulting in overall rotation of
the single cell.
Rotation blocks
0 4 Displacement (mm)
ΔT=40K 2
1<2 1
9
2 Thermal-mechanical design
A rotation lattice and its deformed manner ( ΔT=40K)
The top end rotates by q =15.9° (1=8e-5 1/K, 2=5e-5 1/K, L=100 mm, t=1
mm)。
The angle q increases with more layers.
0
65
Ro
tati
on
dis
pla
cem
en
t (μ
m)
x z
y
q
10
2 Thermal-mechanical design
Simulations
Amplitudes against built parameters for a rotation cell (ΔT=40K)
Linear relation is observed between q and L (q and Δ).
In Fig.(b), we fix 1 and increase 2 to get different D.
(b) (a)
11
2 Thermal-mechanical design
Simulations
Actuation capacity for a rotation cell
M0
r F
The loading mass M0 is normalized to mass of the cell.
The amplitude q increases linearly with number of layers built.
The built cell (L/t=80) can move a normalized mass up to a order of 104.
q
12
2 Thermal-mechanical design
Pully-mass model
The two materials are written using same polymers with different laser power.
They resemble each other but are different in thermal expansion.
Pre-bending of the bi-material beam is observed. 13
3 Fabrication and experiments
Material A (laser power 35%)
Material A (laser power 55%)
Direct Laser Writting
14
3 Fabrication and experiments
Optical image
SEM image
Unit cell Lattice
Top view Side view
15
3 Fabrication and experiments
q
Experimental and simulation results
Errors mainly from
• Thermal expansion measurement
• Heating temperature
• Manufacture imperfections
16
3 Fabrication and experiments
Translation
blocks
17
Thanks for your attention!
Muamer Kadic Vincent Laude
Main researches
Metamaterials
Plasmonics
Electromagnetism
Mechanical Metamaterials
Topology
Acoustics
FEMTO-ST, MN2S Group