Page 9 - ASME SMASIS 2015 Program
P. 9
Symposia
(smasIs), and as general chair of the spIe smart structure conference Biography
(2014-2015). He is currently the editor-in-chief of the journal smart
materials and structures. He is a fellow of both asme and spIe and is the John madden and his group specialize in the synthesis, characterization
recipient of the asme adaptive structures prize, and the spIe smart and application of polymer and carbon nanotube actuators, sensors, and
structures lifetime achievement award. energy storage devices. current projects include the application of new
high power and torque nylon actuators, the demonstration of a solar
charged battery, and the development of stretchable tactile interfaces.
John is a professor of electrical & computer engineering at the university
TORSIONAL ACTuATORS: ACHIEVING LARGE STROKE AT HIGH of british columbia (ubc) in vancouver canada. He received his bache-
STRESS FROM TWISTED THREADS AND yARNS
lor’s degree in physics from ubc in 1991, his master’s in biomedical
engineering from mcGill university in 1995 and his ph. d. in mechanical
Professor John Madden engineering at mIt in 2000. madden is an author on over 100 papers and
electrical and computer engineering several book chapters in the ield of electroactive polymers, as well as an
university of british columbia inventor on 14 patents and applications relating to eap materials. He is not
vancouver, canada a football coach/commentator or movie director, though he does coach his
7 year old son’s soccer team.
Abstract
SMAS BASED MECHANISMS IMPLEMENTATION IN DEFENSE
the simple process of twisting and coiling of materials as common as inDuStry - limitation anD poSSibilitieS
nylon ishing line or as exotic as carbon nanotube yarns results in
remarkable actuators with large stroke (20 %) operating under relatively
large stresses (10 mpa), and producing 100 x the work per volume of Mr. Royi Padan
mammalian muscle. these torsional actuators deliver more power to mass rafael defense systems
than an internal combustion engine, and spin at 10,000 rpm or more. What Haifa, Israel
is the secret to this impressive actuation? the key is the substantial
mechanical ampliication obtained from the helical structures, akin to the
response of a McKibben artiicial muscle. In nylon ilaments tight coils
produce larege strains through ampliication of the relatively small axial Abstract
thermal contraction (1.5 %) and moderate radial expansion (> 4 %). In
carbon nanotube coiled yarns strains of 9 % are achieved by generating shape memory alloys are well known for several decades. their ability to
swelling perpendicular to the stif ilaments that make up the yarn. this undergo a mechanical - thermal phase transformation as well as their high
swelling is achieved by inserting wax into the yarn which expands as it power density ratio is overwhelmingly cited. yet, even though medical
melts. another method involves the electrochemical charging of the yarn, grade super-elastic nitinol is used world-wide, the shape memory efect is
with ion insertion resulting in swelling. absorption of gas or liquid also rarely used. It is especially noticeable in the defense and aerospace
works. When the ilaments and yarns are twisted but not coiled, then applications where engineers seek light weight and small volume solutions.
rotational actuation is observed instead, producing unprecedented the talk will debate smas based mechanisms usage in defense and
torsional deformation at tens of thousands of rotations per minute.
aerospace industry: limitations vs. potential. It will cover some examples of
these torsional actuators rely on a helical anisotropy in active mechanical rafael’s smas based mechanisms which are under development and will
properties. In nylon and polyethylene ishing line and sewing thread address some essential milestones needed to be achieved for smas
insertion of twist produces a tendency to contract along the direction of implementation, within them are smas with as high above ambient
twist as these are heated, leading to untwisting. this untwist is ampliied by temperature and the need for the standardization for testing smas proper-
the radial thermal expansion. Coiling of the twisted ilament converts active ties (covered by AvSI , Afe 77 efort).
untwist into linear contraction. this linear contraction is the inverse process
of the torsional deformation that is produced in a helically wound spring
upon compression. In general, any material that shows anisotropic actuation Biography
properties has the potential to beneit from a helical arrangement, as the
anisotropy can be exploited to achieve torsional deformation and converted royi padan received his b.sc. and m.sc. from ben-Gurion university of the
through coiling into linear actuation. the mechanisms of mechanical negev (Israel) in mechanical engineering. He has worked for rafael
ampliication of these torsional actuators, the initial implementations defense systems since 2001, focusing on advanced materials and
(thermal and electrochemical), the impressive performance in strain, stress processes, including metals and ceramics processing. for almost 10 years
and torsion, as well as some of the limitations that may be overcome by he has been a key member of the shape memory alloy (sma) team charged
introducing new materials and structures, will all be discussed. with developing such mechanisms as super-elastic torsion-based unfolding
wing applications, valves for space applications, and thermally driven
devices. the team is also responsible for developing thermo-mechanical 9
processes for enhancing essential smas properties. currently royi heads
the “processing, tests, characterization and design of smas components
(smasIs), and as general chair of the spIe smart structure conference Biography
(2014-2015). He is currently the editor-in-chief of the journal smart
materials and structures. He is a fellow of both asme and spIe and is the John madden and his group specialize in the synthesis, characterization
recipient of the asme adaptive structures prize, and the spIe smart and application of polymer and carbon nanotube actuators, sensors, and
structures lifetime achievement award. energy storage devices. current projects include the application of new
high power and torque nylon actuators, the demonstration of a solar
charged battery, and the development of stretchable tactile interfaces.
John is a professor of electrical & computer engineering at the university
TORSIONAL ACTuATORS: ACHIEVING LARGE STROKE AT HIGH of british columbia (ubc) in vancouver canada. He received his bache-
STRESS FROM TWISTED THREADS AND yARNS
lor’s degree in physics from ubc in 1991, his master’s in biomedical
engineering from mcGill university in 1995 and his ph. d. in mechanical
Professor John Madden engineering at mIt in 2000. madden is an author on over 100 papers and
electrical and computer engineering several book chapters in the ield of electroactive polymers, as well as an
university of british columbia inventor on 14 patents and applications relating to eap materials. He is not
vancouver, canada a football coach/commentator or movie director, though he does coach his
7 year old son’s soccer team.
Abstract
SMAS BASED MECHANISMS IMPLEMENTATION IN DEFENSE
the simple process of twisting and coiling of materials as common as inDuStry - limitation anD poSSibilitieS
nylon ishing line or as exotic as carbon nanotube yarns results in
remarkable actuators with large stroke (20 %) operating under relatively
large stresses (10 mpa), and producing 100 x the work per volume of Mr. Royi Padan
mammalian muscle. these torsional actuators deliver more power to mass rafael defense systems
than an internal combustion engine, and spin at 10,000 rpm or more. What Haifa, Israel
is the secret to this impressive actuation? the key is the substantial
mechanical ampliication obtained from the helical structures, akin to the
response of a McKibben artiicial muscle. In nylon ilaments tight coils
produce larege strains through ampliication of the relatively small axial Abstract
thermal contraction (1.5 %) and moderate radial expansion (> 4 %). In
carbon nanotube coiled yarns strains of 9 % are achieved by generating shape memory alloys are well known for several decades. their ability to
swelling perpendicular to the stif ilaments that make up the yarn. this undergo a mechanical - thermal phase transformation as well as their high
swelling is achieved by inserting wax into the yarn which expands as it power density ratio is overwhelmingly cited. yet, even though medical
melts. another method involves the electrochemical charging of the yarn, grade super-elastic nitinol is used world-wide, the shape memory efect is
with ion insertion resulting in swelling. absorption of gas or liquid also rarely used. It is especially noticeable in the defense and aerospace
works. When the ilaments and yarns are twisted but not coiled, then applications where engineers seek light weight and small volume solutions.
rotational actuation is observed instead, producing unprecedented the talk will debate smas based mechanisms usage in defense and
torsional deformation at tens of thousands of rotations per minute.
aerospace industry: limitations vs. potential. It will cover some examples of
these torsional actuators rely on a helical anisotropy in active mechanical rafael’s smas based mechanisms which are under development and will
properties. In nylon and polyethylene ishing line and sewing thread address some essential milestones needed to be achieved for smas
insertion of twist produces a tendency to contract along the direction of implementation, within them are smas with as high above ambient
twist as these are heated, leading to untwisting. this untwist is ampliied by temperature and the need for the standardization for testing smas proper-
the radial thermal expansion. Coiling of the twisted ilament converts active ties (covered by AvSI , Afe 77 efort).
untwist into linear contraction. this linear contraction is the inverse process
of the torsional deformation that is produced in a helically wound spring
upon compression. In general, any material that shows anisotropic actuation Biography
properties has the potential to beneit from a helical arrangement, as the
anisotropy can be exploited to achieve torsional deformation and converted royi padan received his b.sc. and m.sc. from ben-Gurion university of the
through coiling into linear actuation. the mechanisms of mechanical negev (Israel) in mechanical engineering. He has worked for rafael
ampliication of these torsional actuators, the initial implementations defense systems since 2001, focusing on advanced materials and
(thermal and electrochemical), the impressive performance in strain, stress processes, including metals and ceramics processing. for almost 10 years
and torsion, as well as some of the limitations that may be overcome by he has been a key member of the shape memory alloy (sma) team charged
introducing new materials and structures, will all be discussed. with developing such mechanisms as super-elastic torsion-based unfolding
wing applications, valves for space applications, and thermally driven
devices. the team is also responsible for developing thermo-mechanical 9
processes for enhancing essential smas properties. currently royi heads
the “processing, tests, characterization and design of smas components
