Milano, 7 novembre, 2013
Leghe a memoria di forma come
tecnologia di attuazione per la
biorobotica
Maurizio Follador
[email protected]
Advanced Education,
Frontier Interdisciplinary
Research and
Exploitation of Research
Results
Paolo Dario, Director
Cecilia Laschi, Deputy-Director
The BioRobotics Institute
@ Polo Sant’Anna Valdera
Viale R. Piaggio 34
56025 Pontedera (Pisa)
Tel. +39 050 883000
www.bioroboticsinstitute.eu
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Research Areas www.bioroboticsinstitute.eu
Humanoid Robotics
(Paolo DARIO)
Neuro-Robotics
(Maria Chiara CARROZZA)
Surgical Robotics
(Arianna MENCIASSI)
Soft Robotics
(Cecilia LASCHI)
Neural Engineering
(Silvestro MICERA)
Biomedical Signal Processing (Angelo Maria SABATINI)
Creative Design
(Cesare STEFANINI)
Future and Emerging BioRobotics (Paolo DARIO)
Neurodevelopmental bioengineering
Ambient Assisted Living and Service Robotics
Marine Robotics
Roboethics
New research
areas
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Shape memory alloys at BioRobotics Institute
Bergamasco et al. 1989
Menciassi et al., 2004
Octopus
Project, 2013
Araknes Project, 2012
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
OCTOPUS IP (2009-2013)
Novel Design Principles and Technologies for a
New Generation of High Dexterity Soft-bodied
Robots Inspired by the Morphology and
Behaviour of the Octopus
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Soft Robotics
Soft robotics is not just a new direction of
technological development, but a novel
approach to robotics, unhinging its
fundamentals, with the potential to produce
a new generation of robots, in the support
of humans in our natural environments.
The role of soft body parts appears clear in
natural organisms, to increase adaptability and
robustness.
Compliance, or softness, are also needed for
implementing the principles of embodied
intelligence, or morphological computation, a
modern view of intelligence, attributing a
stronger role to the physical body and its
interaction with the environment.
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Muscular Hydrostat:
Constant volume during contractions
Longitudinal Muscles
Transverse Muscles
Oblique Muscles
The muscular system
serves as a modifiable
skeleton and allows
the transformation of
force into motion
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Muscular Hydrostat:
Constant volume during contractions
All movements are combination of the three muscle bundles
Local bending, stiffening, elongation and shortening are possible
ELONGATION
SHORTENING
CONTRACTED
CONTRACTED
RELAXED
RELAXED
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Muscular Hydrostat:
Constant volume during contractions
BENDING
CONTRACTED
RELAXED
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Muscular Hydrostat:
Bioinspired artificial unit
biological
artificial
Transverse
muscles
SMA Transverse
actuation system
Longitudinal
muscles
Longitudinal
actuation system
Embedding material
68-75°
Connective
tissue
Mechanical interface
/ containment
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
PATENT PENDING
Single SMA spring actuator
SMA springs working in water
Working frequency of 1 Hz
Operation current 1.2 A
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Assembly of multiple units
NON ACTIVATED
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
ACTIVATED
Fabrication of an entire artificial octopus arm
260
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
65
15
Transverse springs
Longitudinal springs
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Longitudinal cables
Fabrication of an entire artificial octopus arm
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Artificial arm capabilities
Rest length
Elongation
Shortening
Bending
Multi – Bending
performed by local bends
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Integration in the multiple-arm robotic octopus prototype
SMA actuation
ARM 1
Vision system
Manipulation
arms
ARM 2
b1 servomotor
b2 orientation
Locomotion arms
mechanism
Passive suckers
Image: London Science Museum/Jennie Hills
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Grasping ability of the robot
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Grasping characterization
Minimum grasping radius
Testing Radii
[mm]
Grasping
Effectiveness,
50% distance
from the tip
Grasping
Effectiveness,
30% distance
from the tip
12.5
17.5
22.5
Fail
Pass
Pass
Pass
Pass
Pass
The effectiveness of the grasping
strongly depends on the point where
the object is grabbed.
The use of a conical structure
(instead of cylindrical) enables the
possibility to grasp object of
different sizes depending on the
distance to the tip because of the
spiral shape it forms when actuated
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Operating limits angles
Max angles achievable by
SMA longitudinal springs
Simple bending
Operating Limit
Angles
[deg]
a0
85
Single change of
convexity bending.
Operating Limit
Angles
[deg]
Double change of
convexity bending
Operating Limit
Angles
[deg]
a1
78
a2
76
b1
55
b2
44
c2
57
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
SURGICAL ROBOTS
FOR MINIMALLY INVASIVE SURGERY
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
INTRODUCTION
(A STEP THROUGH MINIMALLY INVASIVE SURGERY)
LAPAROSCOPIC
SURGERY
• less invasive then open
• fast recovery
ROBOTIC
ENDOSCOPIC TRANSLUMENAL
SURGERY (NOTES)
SURGERY
• performance improvement
• invasiveness comparable with
laparo.
Derived by
endoscopes
• no “external” incisions
• less invasive then laparo.
New instruments
Miniaturized
robotic systems
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
ARAKNES RESEARCH PLATFORM
(TROCAR/NOTES ACCESS)
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
(www.araknes.org)
ARAKNES RESEARCH PLATFORM
(www.araknes.org)
(TROCAR/NOTES ACCESS)
DOCKING MECHANISM
• Assembly
of
modular
components dependant by the
features
needed
(electro-cut,
gripper, etc)
ANCHORING FRAME
• Safe in deployment and in cause
of fault
ROBOTIC MODULES
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
ANCHORING FRAME SPECIFICATIONS
Actively change configuration
Guarantee a stable adhesion during
surgical tasks
Respect anatomical constrains
during deployment
Embed miniaturized actuators
Experimental evaluation
of anatomical constraints
WHY SMA ACTUATION?
•SMA provide soft actuation and inherent compliant muscle-like
behavior (low forces applied to the environment)
•Compatible with magnetic anchoring
(it is hard to use electric motors close to permanent magnets)
•Easy to miniaturize, compact design is allowed!
(it is possible to leave free space for magnets on the device)
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
FROM THE CONCEPT TO THE PROTOTYPE
(BIAS ELEMENT DESIGN)
• ELASTIC BAND AS BIAS ELEMENT
• ELASTIC BAND AS SAFETY SYSTEM!
• THE GOAL IS TO PROVIDE A NON LINEAR
TORQUE LAYING BETWEEN AUSTENITE AND
MARTENSITE TORQUE
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
FROM THE CONCEPT TO THE PROTOTYPE
(SMA ANGULAR ACTUATORS FABRICATION)
Constrain the SMA
wire/sheet
shape
1st thermal
treatment
Thermal treatment
~500°deg (depends
by the alloy
composition)
2nd thermal
treatment
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Repeat in
order to reach
desired shape
3rd thermal
treatment
ANCHORING FRAME
M. Salerno, S. Tognarelli, C. Quaglia, P. Dario, and A. Menciassi, “Anchoring frame for intra-abdominal surgery,”
International Journal of Robotics Research , 2013.
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
ARAKNES RESEARCH PLATFORM
(www.araknes.org)
(TROCAR/NOTES ACCESS)
DOCKING MECHANISM
•Stable connection of robotic
modules with the anchoring frame
ANCHORING FRAME
• Cubic docking base shape
exploited for constraining the
rotations
ROBOTIC MODULES
• 1 active degree of freedom to
execute the docking
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
Conclusions
SMA are still limited from the point of view of control…
The use of Shape Memory Alloys for actuation represents a technological opportunity for replacing the
today's electro-mechanical actuators with simpler, more compact and reliable ones.
From active and
smart materials…
Strong mixture of expertise
Leader in consumer electronics
Leader in SMA providing
and manufacturing
Leghe a memoria di forma come tecnologia di attuazione per la biorobotica
…To robust
and reliable
actuators
Thank you for your attention!
Paolo Dario, Director
Cecilia Laschi, Deputy-Director
a memoria
di forma
come Superiore
tecnologia diSant'Anna
attuazione per la biorobotica
The Leghe
BioRobotics
Institute,
Scuola
Polo Sant'Anna Valdera - viale Rinaldo Piaggio 34, Pontedera (Pisa)