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BIO Distinguished Lecture Series – Sheila Patek

BIO Distinguished Lecture Series – Sheila Patek


Bill Zamer was the program manager
who was the person who first explained to me how to write a grant or what was
involved who gave me a term called mentoring food systems which I’ll come
back to later but I wanted to acknowledge the stuff that you all do
which sometimes I can imagine it’s tedious but answering the phone setting
up those meetings responding and giving advice is actually central and you want
to know this like ality that you might even be here today I also wanted to
point out that I’m actually currently funded by what’s called an Erie from the
department and this is a basic research grant only it’s an interdisciplinary one
and it’s been my central focus for years at the five-year grant and what
you’ll hear about is how these two efforts have together and I also want to
point out the inspiring language from both you know some people don’t realize
that NSF’s website includes the word national defense and most people don’t realize the DoD so it’s a nice confluence and recognition of the group
today overarching this theme of my talk today is what it means for research to
have impact and when we talk about basic research this is a conversation that we
have in our families in our classrooms and in my case with Congress members of
Congress and I wanted to start by just asking you all in your mind to think
about what it means for research to have impact and I’ll cover an ongoing
discussion today about what that means and I wanted to contrast two events in my
career that were fairly significant that relate to this so back in 2004
I gave a TED talk which in the intervening years has gotten 1.4 million views
now as scientists we can feel good about this but in reality my favorite yoga
instructor – she gets that many hits three hours after she posts her videos right
but in the science world that’s a lot right underneath this I periodically look
at the comments and a few years ago someone wrote – and I don’t know who
this is – I’m a bit worried that I’m finding this stuff interesting as although the implication
of that research and the benefit to me and our problem is real and a couple
years later someone wrote sarcastically yes because mechanical engineers will
never find any usefulness in a system that can easily break hard materials
of course this is a talk about mantis shrimp breaking things so even online these two people
are talking about their view of what’s impactful and what I find most
interesting on this first post is someone actually downgrading or not
respecting the value of their own curiosity and engagement in a topic and
the nature of the exposure to new knowledge and how that is a quality of life experience I trust that with a couple years ago in
the span of a couple of months over three million people watch the PBS
Newshour op-ed that I did that talked about how I interacted with Senator Flake
one-on-one after he put my work in his waste book and how again
when we were talking he again pointed towards what he viewed as the most
impactful which was the development of new materials for the feds, football,
whatever and I really got to point out because I feel like some of our
discussions are either basic or applied or curiosity is not a good justification or
something else and what I talk about in my classes is that every answer they’re
all good and there may be different answers to that question of any who are
even in this group even in a basic research so our decision so this will be an arc
that I talked about today research and the nature of discovery of just simply
seeing things for the first time and how that starts to build out into a
cross-cutting interdiscipline and beyond oh and by talking about the ecosystem
that largely the NSF is facilitating so let’s start with this notion of what is
fast we’ll start with mantis shrimp are mantis shrip this is a spearing mantis
shrimp found off the coast of Australia a little in Florida about this big this
one and they dig burrows in the sand and they catch fish swimming overhead this
is a video I took eons ago those of you who remember those days but you can
basically see this animal reaching up and catching things as it’s in contrast
and related animal as it’s smashing them two shrimp there this one’s about the
size of the cigar found in Australia this animal is processing a snail shell
and it sets it up it moves it into different positions and then breaks it
so this animal is taking a small hammer that’s body and breaking a cell shell
that I could jump up and down on for years and probably not break or maybe
chip slightly and it’s doing it with Oh so what is happening here and is we’re
seeing some extreme animal capabilities and about you know over a decade ago not
understood or even visualize what they were doing they can slow the video now
this is a tiny mantis shrimp capturing trying to capture a feeling after a
brine shrimp and here’s a smashing mantis shrimp knocking the claw off of
the crab so a logical question is how fast are these animals moving and what
is what did what are they doing so at the time when we first noted the speeds
of the smashing mantis shrimp as the first animals we studied we discovered that
they’re moving at highway speeds the acceleration of a bullet and a gun in
less than two milliseconds so this was pretty cool and set this out as a like
if abilities in biology in the meantime though my graduate student at the time
Amanda Vries decided she wanted to see how
fast spearing mantis shrimp are because wow they are capturing fish going overhead so
they must be much much much faster so years would tick by and she’d come in
with more data and it kept coming in really slow now for my biomechanics
ladies in this group you know that this is not slow at all that’s the stuff
that’s six meters per second in the squid strike six meters per second is
like you know people jump around and dance in the vertebrate world with
something goes that fast and what I realized is she finally came in and she
said Sheila this is fast this is something else
entirely and I realized with our ability to assembly visualize the world of
incredibly fast actually redefine what is fast so if we line these up our
canonical cheetah is here about 20 meters per second down here in terms of
acceleration and doesn’t even register on this scale but I believe does but
what you can notice is that some of our fastest organisms are doing many
different things the fastest organism that ever been recorded is the Stinger
on a jellyfish so not only do we have to recalibrate what i’s fast but we have
to recalibrate our notion of what is fast for because up until up until that
time our thoughts about fast is all about predator prey pursuits in fact even the
cheetah folks have re-stated where cheetahs fit in in terms it fast they’re
not that fast they’re fast for a locomoting animal so when- if- some of you might do this you find a document and that an extraordinary extreme in biology
the world looks in and says it holds this up as like the most amazing thing
there are like fears of them taking over there’s actually several science fiction
books where there’s like this dominated but really as a biologist when you see
something happen we’re above a certain speed but cheetahs there’s not a whole
lot of locomotion why not wait why aren’t the spearing mantis shrimp moving
its fastest now I have the same machinery which they did why don’t they
go so fast so then it gets you into a space of thinking about trade-offs right
what do you lose when you go so fast I’m gonna come back to this a little bit
later by point 5 these are going to talk about the trade-offs of things I’m gonna
come back here to talk about interdisciplinary and how our ability as
biologists think about trade-offs is much richer space for translation then
thinking about ideals about the ultimate perfect fastest creature we’re gonna
come back but for now let’s talk about why it takes a long time to be extremely
powerful in the world of locomotion and movement it is completely dominated by
what muscles can and can’t do now I know this is a broad audience so what I’m
gonna do is I’m gonna try to give you the absolute bare minimum to get what
I’m talking about and I can happily go into it like at least a three-hour
deep dive on every single slide oh so feel free to ask me to dig a
little deeper as we go or after after the talk but basically this kind of sums
it up if you want to lift something big you can only lift it slowly if you want
to throw something fast and be small this is called the force-velocity trade
off and this trade off determines if you multiply the two you can get work output
but it also determines output power in the physics sense or sorry work per unit
time this is masters if they power output for the physiologist because
there are physiologists in this group – Steve Katz who taught me in grad school. I can’t believe you’re here today very cool thank you so the point though is it
physiologist we are taught from the get-go that everything to do with fast movement is about hitting the limits of what power muscle it is as much about
what muscles can do as it is about what muscles can’t do when I started working
on this interdisciplinary team the MURI team I think it took maybe four or five
months to get the engineers physicists mathematicians to even understand this
curve at all how did how do we get these numbers and somewhere along the line I
had this like horrible sinking feeling which is that actually everything has a
course velocity everything is power-limited that you’re going to want
to take the weight off of it it actually will speed up and I suddenly realize that we have
this entire paradigm in physiology about fast movements which relates to the
power limits of muscle when in fact this fast systems don’t use muscle at all
none of the extremely fast movements in biology are produced by muscle which is
like a total disconnect but if you just think about power limits from a physics
point of view it’s everywhere and all of a sudden physics comes in so let me explain to you how it’s set up in biology we talked about the maximum power output
like muscles because you have to flap wings quickly and hold level when we
discovered the mantis shrimp striking capabilities we measured their power and
what we found is that they could produce 10 to the fifth watts per kilogram
muscle which is impossible this is the most muscles can do if you have a defy
that muscle is muscle power outlet is exceeded that means there must be
something else producing the movement and for many
decades all you would do at that point is say there must be a spring that’s
doing this or a spring in a latch and it really wasn’t until the
interdisciplinary team when I realized oh that’s we’ve structured this whole thing
about what muscles and we identified then we stopped so how are they producing this
movement what in the world I really truly never thought of that until a
couple years ago because of the dominant paradigm theology so what we can say
about extremely fast movements and management trap-jaw ant’s other a lot of
insect jumpers is that the muscle loads the spring it loads the spring on the
force end of the force of the curve meaning that it’s a very force modified
muscle and of course modified is also good it takes a long time to load a very
stiff spring that spring releases the movement and then it’s released to relax
and I don’t think you can find a watts per kilogram spring number calculated
that’s been published – did you do that? you did I love it so they’re very far
and few between okay tongue and cheek aside and engineers generally don’t study this at all I’ll tell you why in a few minutes but let’s
talk about to make sure how do they do it so they have a muscle it’s a force
modified muscle is a low-power muscle and they contract it and they have a
latch that prevents movement early and then the last releases and the and it
flies out this was the state of knowledge when I first started working
on this well we demonstrate is that it needed a
spring so now he doesn’t have a spring that has a linkage system which is used
a lot of biological back to that and the spring is what actually pushes the
appendage, which is the case for everything that’s above basically the cheetah limit
so all of a sudden we now have a mechanism it’s spring based there’s a
linkage system we’re going to come back to this later in the talk but it also
meant that there is a very common mechanical system for delivering and
storing the energy which makes it possible to study this thing from a
comparative evolutionary point of view so we weren’t just solving one unique
problem but we were solving a problem that we could look across the
evolutionary diversity but we decided we wanted to actually measure
Springs were doing so we looked at the evolutionary variation in the springs
this was actually done by two undergraduates and I kind of keep these
phases there one has gone on I got a PhD at Harvard and he just started his first
faculty position it was University in Pennsylvania so what we found is that if
you look across the size of the appendage and the amount of work you can
put into this spring the smashers the super high accelerations backers can put
more power and why that leads to faster movement we think about energy that
makes sense than that we don’t know we also look at the kind of muscles that
they use so this is the size of the appendage this is Arkham your leg
the longer the sarcomere the more force can be developed smashers use high force
muscle the Lotus spring so if you think about this from the perspective of an
archer these are mantis shrimp are taking
muscles we don’t have the flexibility of vertebrates but they have evolved
muscles that can basically load an incredibly stiff spring very very slowly
now we get to the first if we go across this assume all else as well these
Smashing management we’re going to take twice as long to contract this muscle as
the spheres which is a serious problem if you’re trying to respond quickly you
catching a fish or running so it is not a free lunch mantis shrimp they achieve
incredibly high accelerations and speeds take a long time together isn’t going to
work for most applications in biology if that weren’t bad enough
maybe the shrimp track towards all these systems they move so fast the duration
of the move is so fast that the nervous system is blank the motion there is not
enough time for a nervous neural signal and get to it from the brain to actually
track what they’re doing so this means actually I’ve got to plan ahead and if
they’re going to learn they have to order them
and they have to do something ahead of time or to that assembly makes us a big
problem but certainly one that our gisle it takes a long time to get set up
unless you’re using a crossbow and then once that arrow is gone it’s gone
so mantis shrimp are have the same issue and we found that actually the
International postdoc to work with me is back in Japan Australia found and they
do in fact bury the velocity of their strikes by changing the amount of
loading of their spring though they do address upstream what happens downstream
so the question is how do they learn what they are how do they learn
successful strategies for breaking shells or come back about a minute
so when we think about this system beyond the paradigm of high-power motion
but by muscle and we step past this being something special about muscles
being power limited and everything are limited then we get squarely to the
point of asking how the heck are these motions actually generated and the
springs that actually drive these movements have not been characterized
and the reason why they have not been characterized is because our materials
testing machines in biology and engineering are driven by motors and the
motors are power limited so the auto URI team that we’ve been working on a new
device they basically doesn’t use motors in order to test the real power limits
the real power output of the materials so we’ll come back this a little bit but
we plotted out the fast movement analogy where the only things were measured
comparably we’re back there actually any more than this but these are the ones
that are calm and what we could identify is that engineering is way down here but
also these are the mantis shrimp I’m sorry these are the top jaw and it’s a
major actually populated this out a lot more of its broadcast Alyssa Presti it’s
getting pretty cool but just to the left of this or the fast system thing and we
used once so we also started to realize that there
was a material limit do things that you push all the way and then the
self-destruct the systems that could be used over and over again and it becomes
a question of materials in a flow which is a very fundamental in almost Sciences
problem and a physics problem okay not all great to be super fast but then the
other question is what do they get for it let’s look at the mantis shrimp they
are small but they achieve a large animal perform so we put these functions
up here there’s nanoscale puncture impact low Reynolds number lunches
impact all monster let’s go look so get all this here we now know that for the
most part because those are not used for locomotion for the most part we have no
idea about the dynamic of these interactions with the environment and
yes well we can get a few clues from the management
so this mantis shrimp is was sold at 30,000 frames per second and it has
hammers each hammer is equivalent to the mass of two toothpicks and here it is
breaking a shell that I would need to use a heavy hammer blow to break and
what you’ll see are the shells breaking apart and you’ll see a flash of light
the video because there’s a lag for this broadcast airship but you can come you
later if you want to see the real time but there’s a beautiful flash of light
in there which is actually not a flash of light it’s the collapse of what’s
called the cavitation bubble you can hopefully see it here a little bit
better but these appendages are moving so fast that the water moves in jason–
jason– areas of water loops one was very fast and when was very slow which
it creates an area of low pressure which creates a vapor bubble and when that
available collapses it’s equivalent to the heat of the Sun it emits light and
emits sound we can’t actually see the light when we can certainly hear the
sound of this collapsing this is one of the most energetic events ever described
its singular area of focus in physics and actually look for a little while
there was paper than someone who’d managed to get nuclear fusion going in
there but it was retracted from great great Charles so anyway but more
to the point capitation is a bane of the existence of people who design boats and
VOC repellents if you spend a boat propeller fast enough it will wear away
though mantis shrimp are using this a great effect but they also learn their
impact patient but of course they can regrow they molt and they regrow there’s
also a problem of being quiet so military understanding cavitation
forever because if you speed up a boat or a fish for that no matter what you do
it will cavitate so another interesting piece is the speed limit on mantis
shrimp and other fast features that are trying to capture prey quietly as
opposed to generating a huge din in the ocean most of the noise and biological
noise of the ocean from mantis shrimp snapping shrimp and all these agitators
who decided they don’t care that they’re being noisy but the rest of them are
trying to be quiet and it lowers their speed limit so at the time back in the
day when I did this work it was hard to believe that an animal would be even
doing this so we developed a force sensor system
where the animal could hit the force sensor because we will record it
impacting the cavitation with sound and distinguish between the two and what we
found is that in fact there is a cavitation bubble in between the sensor
and the appendage and frankly everything they hit forms a cavitation bubble when
it collapses and notice I won’t be here over there is a lag Tara its undoing
later but we can slow it down even more you can see at a hundred thousand pages
per second the hammer coming in to the sensor it will hit and then it will
bounce off the bubbles are collapsing that’s the collapse of the cavitation
bubble and we can actually see this on the four sensors themselves so that’s an
impact and then it was the formation of a cavitation bubble sometimes the
cavitation is double the height of the initial
impact so what does this mean for the animal and it’s biology Wow I’m usually
like the fastest speaker ever but the delay with the slides this week you we
have to talk faces so maybe like hardwire this thing it’s good so what
does this look like in real life for a management it means that for a given
strike with two advantages they generate 440
it’s the forces on the my ax compare that to one shark that is biting it also
eats shells if you look at the scales of things this is the bite of a horn shark
onto a force transducer over milliseconds this is microseconds that’s
the peak force of a mantis shrimp now balanced about all this stuff is way up
there this is a 40 gram animal and that’s a 33 kilogram animal how does
this break the shell we still don’t have an answer to that adhere it to the
physics end of things you know that the area under these curves relates to the
energy that’s involved so the area under these four Peaks is tiny compared to the
area under a job based L breaker this is a very very very low energy high peak
event that somehow breaks the shells so we can express this even in a different
way so one of my beloved by DX o u s– went and did a nice comparative study of
mass of an animal their bite force yes my colleagues do put force transducers
in the mouths of all kinds of animals their semantics trips peak force and it
lines up with the highest force mammal anyone know if this would be I mean up and you know so one of what
we’ve discovered is an alt logical strategy these little do a little tooth
paint the that they’re doing allows this little
animal to eat a big shelf and get into it without very much energy so it’s
really another way to look at is totally unique if this if this in this graph
anyway it’s like unique in general Baldy way to give it to you larger prey so if
the highlight was to lighter things and 4r6 just having duty stuff the section
that that light um Rachel crane was my lab manager she’s
now got to see that Stamper she decided she wanted to know what do managers know
about snail shell so I have was interesting someone for a position in my
lab and he walked into my car and he started to freak out and I was like what
is wrong he was like not even speaking clearly and I’m like what is wrong and
he finally gets out of his mouth he’s like your mantis shrimp are all in glass
tanks and I’m like yes they are Allen what is the issue they’ve been in
there for 15 years why is if you like but but you’ve given all these talks
about extraordinary attack forces and I think I see one hit me through the tank
you’re pretty glass tanks shells it’s hard stuff if they can’t break a glass
which should be easier to break – oh you know what Rachel was there she said well
why don’t we gave them different kinds of shells and let them talk how they can
tell the difference or what do they know what they’re doing so what she found you
can see they’re sort of on video um they’re adjusting the snails
this animal rotating it around placing it in place thoughts to clean its
eyeballs you know important things in life sets it up it will hit it hopefully
you can capture that put it streaming here and
actually break the sale shall put the backup she was getting elected by the
Osho the single shot that worked and I’ve actually got it in place and
eventually it’ll hit knocking the top off of the shell and then bolt it up and
what she discovered is that in fact they do they hit the shelves the sequential
systematic behaviors that are specific to spell shape oh my favorite perhaps of
all time that she made which is which shows the three different shell shapes
and the region of the shawl that they’re hitting a yellow color and you can see
just from the color that you could give them a high spired shell their start
here at they’ve they do in fact have strategy for where they break so they
must have someone or standing and this is something that we actually do need to
know in terms of how to bring ceramics and turns like this what is what is this
type of strike affected for and clearly use man determine the best access and
efficiently access the inside of these cells and the meantime an undergraduate
in my lab demand the Kesari she actually just started medical school on a full
scholarship and he’s sitting there watching the stock that she wants to use
our 3d printed that that was relevant to a future of medicine hopefully will be
and she worked me a lot for her full four years at Duke and so she thought
well what if we gave them patients and asked them to tell us behaviorally what
they know about the shape and what how are they processing it so this in this
one what she discovered is that in fact this little cylinder that has a hole on
the side with food the management will actually ignore the hole with the food
and instead cue in on the edges knowing somewhere whatever that their
access inside here relates to state in strength so we’re continuing this work I
thought that was so innovative really cool project this okay this is those are
some of the highlights and the ways that we think about
that’s what you get and what you lose when you go to the other extremes in
biology but as I mentioned earlier probably would not have even continued
to work on manuscript system if I had it realized early on that there was a
morphology and that we could study efficiently and effectively across e
because what I’m really interested in is not just the physics and the panics of
how these systems work but how that relates to evolutionary diversity so
again a question here is if you evolve something that’s incredibly potent does
that help you out or are there trade-offs that come with it so this is
a really long series of papers that kind of work by three postdocs Toma Han as a
professor at University of Montpellier the later sent to the professor Illinois
yeah Martha media was just sort of in a position really really talented
scientist and I’m barely going to touch what they did but what we came up with
was a way to compare morphology and mechanics and integration of the
morphology across manage and ask what does the evolution of it I accelerated
system due for their potential for evolutionary change and in the meantime
I’m working hard to make this a system that we could even generalize and
compare across many groups of independently evolved linkage systems so
in a very short format summary what we found is that with the oranges and as
I’ve already told you it’s extreme acceleration a more potent spring
although we don’t know the dynamics of these Springs yet they force modified
muscles this is the part where it gets a lower muscle to put more energy into
that spring their body sizes back to that in a minute so this is a very
process is actually very fluent reader over the management but before the
Mantis snatchers evolved there was a very wide seismic editor but all centers
are small back to what we found from a series of papers is that with the origin
of the hammer was a martini in the accumulation research that’s on
that Oh it’s called disparity the diversity of
morphology which is the first hint that may be evolving incredibly tightly knit
and tightly tuned mechanical system actually reduces the potential for
evolutionary diversification abacus in a minute but this is something that
engineers who are doing synthesis to think about all the time how do you
retain the ability to vary the system and play with it as you get it tighter
and tighter and more and more extreme so one highlight from all this stuff was
looking across not dismantle sharklet multiple origins and fish to ask about
the correlation between the output of the system and the morphological in and
how that relates to the rates of them how does that work so this is a fairly
complicated project but just to give you the kind of icing on the cake version of
it what we found is that if you look across linkage systems this is the
linkage mechanics that actually delivers the energy to the motion of the hammer
of the mantis shrimp or the jaws and various fishin’s the most tightly
correlated parts the parts that are that if you look at a change in the output of
the change in input ones are most highly correlated back to evolve and not only
that but those parts are always the smallest so what we found is actually
it’s something that is very well and for thinking about evolutionary the
intersection between physics and evolution as well as for engineer
synthesis is that tiny parts can be an incredibly important part source of
variation of illness for a long time in biology that can be tightly coupled to
the output of the system and in fact that could be an accelerant or a way for
enhancing the rates of evolutionary change so in the same system where we
can find decrease accumulation of diversity because of shift you
potentially kind of a shook it tightly knit by mechanics we also see a robust
pattern across multiple room a pathway for enhancing the rate of
evolutionary Chi so this has been really exciting for us you’d be able to take
this further further steps out as more general principles or mechanical system
was an evolutionary diversity so we could even go from this process we could
start with a simple we good system and presumably we could do this in physics
and so this aside and say well where do we marry the very sensitive to
mechanical sensitivity we can look at the diversity diversity of these
different components we can think about it in terms of rates and we’ve also
looked across the actual topology of the look at how this manifests as shifts in
evolutionary chain across and again these tightly linked components are all
biased on the tree to the change on the trees by his title correlating ok so how
does this fit into an interdisciplinary paradigm and one of the things that that
I feel so strongly about is a little bit about this today when various people
here is what does studying all this biology actually offer in
interdisciplinary groups so needless to say I obviously think wild you have a
lot to offer that’s kind of goes without saying but I wanted to return to you a
couple of these what people have done with these discoveries so on the side of
engineering looking to biology for extraordinary paradigms and perfect name
yes these are some really important examples this is a recent bring many
people I do not work with these folks I’ve never actually talked to them characterization of the right because
shape instruction is very important for developing the capabilities I’m
something that engineering engineering has a lot more cereals at their
fingertips but a lot less in terms of way
which is what biology plays with and then the Casillas lab did a whole series
of projects where they’ve actually developed materials that are fracture
resistant interestingly inspired by my pen time at that minute the world
without outreach and impact for interdisciplinary stuff and we think
we’re talking to the public we’re actually talking to a pre huge worldwide
community of people understanding problems
Susanna Cox was a graduated in my lab a postdoc at Penn State she builds a
physical model mantis shrimp and when she started this is really the engineer
said that that was actually impossible and I said well I’m actually a mechanist
and I know my numbers are real so it has to be possible build this thing
now whether there’s an engineering pathway to tolling is a different
question but he’s a phenomenal machinist and as well as an alibi object great
engineer and she built a physical model a man to ask whether this whole
cavitation that this was an accident but what it’s actually helping them break
these materials and instead she stumbled she did that and she stumbled on
something really interesting which is that when we attach even a real niche do
the physical law bullet lakes beans they always cavitate they’re in forward
motion and in fact theoretically they’re exceeding the speed limit for cavitation
when they’re rotating and I’m putting this I know this is gonna be post up on
YouTube so it’s like a call to universe I think this that they’re doing
something really interesting dynamically the magic of are the press cavitation
through a path through the water and even if we have just the tiniest little
things to the appendage it will set up there might be some really interesting
stuff here that we discovered accidentally about how to suppress
cavitation and rapid movements so I don’t know if the big thing except that
we set out to study intentional cavitation in manager and discover that
that they’re actually not cavitating when they should be which sets us off in
a whole different direction thing about our colors and
suppression but I wrote this this commentary incites a few years ago which
is articulating this issue of what what is a training biology what is it good
for or how do we move away from Linda to extreme systems and then trying to build
another version of it in engineering space to instead thinking about a broad
interdisciplinary frameworks and principles that enable really
broad-based discovery and I chose the gecko adhesion as simple of this where
the people looked at gecko and he’s forever because so fast thing they could
run and do all this stuff and there was this development of a product called
geckskin which is that black sparkly stuff that
sticks to everything and there’s a lot of turmoil in the community about
whether that could be called a better or not the terminology of like what’s
bionis bioinspiration what’s biomedics but what i wanted to focus on is what
they did to figure this out and what they did for this out was go to
fundamental principles and then look at how those fundamental principles of
adhesion are manifested in the diversity of geckos and what they found is that
you do not need a lot of hairs to get nano sized hairs to get adhesion you
just need close huh which that allowed them to produce an incredibly cheap and
simple adhesive structure by looking at the fundamental principles and then as
an evolutionary biologist you don’t want to accidentally be focusing on one
species that’s found here way off your theoretical foundational curve because
what you’re doing is you’re studying in really interesting what you really want
to be studying is that curve and then why that system is off the curve i
talked about this in the context of a network of trade-offs expressed through
evolutionary diversity and if but we need a nurse disciplinary understanding
of chemistry and adhesion alls other stuff and get that golden line of the
core physical principle but we need a biological understanding of variation
and evolution and then make use of this diverse dataset to look at how these
trade-offs have been since all the different environments so we’ve been
doing that in the meantime and we published it a paper – this past
year it was led by mark Elton a postdoc in physics
he’s now harvey mudd as a professor this is just a short a small picture of the
team involved we talked a lot a lot about this today and my various meetings
with folks we our goal was to establish the basic physics of fast small movement
using a language and math that anybody could understand now for those of you
who have been involved in a disciplinary efforts I cannot overstate how hard this
was and I mean it was it was the journey getting of this talk are realizing that
our force velocity curve that we’ve been studying is a special thing about muscle
and biology it’s just a generic physics problem and muscles muscles expresses
the force velocity trade off in an interesting way but there’s nothing
special about that or that nobody’s been measuring real-time stream mechanics
because we’re all using motorized materials testing machines that don’t
allow you to actually measure them at that hour and that so we we set this up
and we realized that what it is that with the key transition points or when
something should be screwed and driven we also realized that there was a much
richer and tunable so it would just be all of the muscle
where the motor limiting power output therefore we switch to a spring and a
lash therefore we got something growing out in fact what it is is you can switch
and you can do big time do you increase your takeoff velocity increase the
duration and this of course is what biology plays and this of course
enriches that it’s fear of synthetic design you notice wanna look for a
spring and everything just cause you want to first spring in something in
order to do actually whatever engineering side report filed is
expressed that in many ways so now with this in place we not only have been
populating the space of biology but we’ve actually moved and
words of magnet up this wasn’t broadcast I would like a cheerleader but instead
of really exciting you work across teams and say well our shared space here is
physics math model it’s fundamental understanding biology is offering you a
matrix of ways to do this let’s see how engineering synthesis and tap into those
same principles and push that in directions make sense
instead of making a model manager just cuts right because it’s so cool and it’s
okay so that to me is my vision of the connection between a training in biology
and evolutionary biology and our ability to do achieve these kinds of translation
so when we look at this list of what I really what I’ve done is I’ve talked
about the evolutionary diversity and this rich data set for resolution of
trade-offs I’m moving to the obverse thing we start
with what is fast we have to throw out the notion that she’s other then we have
to then think about well shoot why aren’t things locomoting that fast there
must be some things that come along with being that the main locomotive kind of
possible so with that owns the need to take a lot
of time hello energy into a set structure you have to use that same old
physics rule it’s slowing down to increase force output fascist Universal
we could talk about in these animals it turns out that generally speaking if
you’re going to go that fast and you’re gonna propel something with a spring you
have to be small so small animals are essentially using that half way to
access large prey and with this of course are the issues of the fact that
these movements are so fast that there’s no real time oh do you have to embed
issues related to learning and control outside of the movement itself well not
only is this a trade-off for biology but this is a fundamental issue for engine
so army regime we’re constantly working on how do we tie in our notions of
control theory which it turns out are there
but don’t necessarily rap easily into a system where your slow loading and fast
controlling through spring latch systems and finally this view and the
integration that tight integration of mechanical systems both slowly down the
accumulation of evolutionary diversity but at the same time providing a pathway
for tweaking it again an issue that anyone who’s doing engineering design
think about do you keep it loosely coupled with many parts an able
flexibility and variability or do you glom it together without much room for
change in order to achieve and more extreme output this reflects all the way
to the evolution of a scale and finally that this idea that this is what
biologists are good for these teams many things but not the least of which is an
ability to think about evolutionary diversity and variation on multiple
scales from individual variation on up to evolutionary variation and how that
viewpoint is a much richer space for people coming in and looking to biology
for inspiration so I wanted to add by talking about this question of impact
and how I hope that it’s reflected itself at that time one area of impact
is this the organisms themselves how people engage with them and I think
that’s one of those early comments that we we talked about with someone being
like whoa that is not interesting but that must be wrong and I have to say I
don’t think that that’s wrong I think that is in their way of engaging with
the world that we live in it’s incredibly important and it is very
valuable the same time we can talk about the individuals and the artwork I mean
my former lab manager made the entire book don’t link with Shutterfly books of
artwork from the internet these are a few that people in the lab or people
that shared with me that’s an area of impact right this sounds silly but there
are entire like videos in lines and toys and mugs and stuff on people being
interested in an organism it’s not an impact it actually is it has to do with
small businesses and like business in general business models I should say by
nothing I’m not like holding that scrap this off-camera the other area in pact I
wanted to mention is my NSF Korea grant paid for an NSF recent experience for
teachers and I had teachers in my lab for five years and if I had that she’s
one most rewarding arena of impact it was death I have these teachers come in
with it and they work with us half the time we’re working with them they’re
their curricular development and the other half the time they’re doing
research when actually published a paper and the dog world side again tripping us
up like I couldn’t even get that done their work really hard we also work the
art with the army educational outreach program to bring in not a grandma high
school student we had to we had to for multiple years now I’ve talked to a lot
of you about this initiative which was a launch to an effector grant it’s a it’s
a program that matches students and mentors in a transparent and the
mechanism that combats implicit bias we have their names off and there’s a whole
bunch of things around that and they’re actually moving it to university-wide
program it’s now Duke strategic plan and by the end of this year we’ll be
launching at a platform that any university use that was funded by NSF
career grant a bunch of people to help you build those with this is also impact
these are bunch of my lab first at postdoc earning a postdoc of the Year
award from Duke this year I don’t think we can understate you get back that we
have one-on-one individual by individual in the community done career this here
the press side is both a thorn in my side but also it is a Dallas or
interdisciplinary exchange as I mentioned these folks at the top one but
these two they learned about my work from the TED talk I have never met these
people so when we add this a lot of people will see these stories we read
them and think wow I had something that can there so yes it’s impactful to the
public but also for interdisciplinary exchange the impact of stepping back
becoming more engaged on a multidisciplinary level and I wanted to
end by saying there are impacts here that just are getting out there
eating stuff and embracing multiple an interplay agreed that you liked this
stuff but this person hopefully has come to recognize the value of their own
interest and an impact and this person obviously was sold on the argument for
why this is profile so I wanted to end by just saying this is the foundation of
it we’re transpire the invisible we5 joy in
the unexpected and bored and at the same time we are compelled to improve the
human experience and the human experience is all of a thing so with
that I’m gonna thank you all and there are so many people who we have
microphones this one is I think the most interesting question is how those
extremities of the shrimp are moving through viscoelastic media like what
what is happening on the nano scale around that interval because have clue
to understand that fastness of movement the laminar flow is a turbulent flow how
much energy is lost of it better I have you can you say something first more
seriously it turns out that in the realm of
extremely fast movement we can do things like computational fluid dynamics and
concede the water all of those off-the-shelf systems and approaches
work until avocation gets involved then you move over into the realm of very
specialized analysis tools for like for example fuel injection engines it’s so
complicated what they’re doing that I have never been able to get traction in
my lab or through collaborations on the fluid dynamics of that motion it is so
sensitive we’ve always wanted to do automated backing and I can put you know
a order of a millimeter either smaller blue that on the appendage and it will
totally throw the thing into chaos but be this cavitating and all this others
so what you’re actually asking to me is centrally important and very not easy
and I have no idea I mean we can seed the water but the moment we get
cavitation going on you know the seating with like part limited all intimate
rates up like that that tells us a little bit but again what we hit is
technological limits not just the computational modeling but actually of
imaging so I have all these people who come to my lab from other arenas of
motion whether it’s engineering or local motors and they all are very happy
because now high-speed imaging has a great big grid of pixels that you can
film everything at five thousand I can’t you get more points they come to
my lab and they’re like what the heck all I see is pixels and the thing isn’t
done we’re talking it over three hundred thousand frames per second the standard
is five thousand feet per second we’re told me that over three hundred thousand
rays per second and we can’t even resolve the particle motion happening at
these scales so we’re just sitting right at this frontier that’s a frontier for
everybody not just biology so it’s really exciting so I’ll return to that
initial point of it if you or someone else covered or here wants to tackle
that there’s so many good things work so you didn’t really address the glass
tank though you’re saying it’s like it’s not motivated to break the tank again
modulae they hit it hard oh I know are you so much satisfied I’m
not satisfied I was like I’m bad too like engineering departments all over I
think I’ve been at the Virginia Tech evidently you name it and and I’m like
you need to tell me what’s going on here and the answer as well probably if the
two surfaces are curved it makes the the point of contact really tiny which then
concentrates the energy which will then you know cause of thing to fracture so I
knew that we even spent time with some folks from Purdue working on bar I don’t
know how many on the Argonne the Advanced Photon Source Argonne hoping
that if we did x-ray we can see the inception of the fracture and get some
sense of the dynamics of these systems and it’s invisible to us so it’s so cool
because I mean it’s frustrating I like to work on problems like saying but the
the cool part isn’t that this is this is not something special to biology we’re
heading technical limits that are common to everybody and it’s very interesting
to know what you get and what you lose with a teeny tiny toothpick mass I
impact at the bullet like acceleration which we basically can’t build yet in
engineering in terms of materials and acceleration and brake ceramics but not
a glass tank mysteries I know I know you want me to answer that but I’m like I
did I guess really the goal of these talks is what I say in my lab is to make
you all curious so those are good curious questions that I wish I could
answer yeah and I hope this inspires other people to take
a local succulent had with this wide moving slowly had time to go okay so
these guys are really fast yeah so so some people asked today why why did you
you would find in your address we have small fast things and it’s not the small
fast things it’s small fast things can be that can be used over and over again
that don’t self-destruct and this is why we’re exploring daddy that when I saw
that graph of acceleration and math why there seems to be a hard stop where if
we move to smaller and higher acceleration there self-destructed
system so at some point the material itself most likely can’t take any more
energy in and actually you’ll appreciate this Emily because some of you in the
biomechanics level know Steve Lobel and passed away a couple years ago and
there’s a long history in biology of talking about speed when that’s being
based on muscle and on volumetric scaling see before he died right around
the time when I started to work on the crash site he kept saying if she has it
in his textbook overbooked it non-secular
look a few years ago um that he could plot size and acceleration and his point
was that he could do it for animals and he could add plants on there and they
would fall in the same way it clearly had nothing to do with muscle and
clearly it’s nothing to do with some volume leg scaling thing and his point
was it’s the limits of materials so this to me is also wildly cool because if not
only were interested in hitting limits and seeing how that’s how that’s
manifested in biology but we all know that engineering
synthesis a much richer array of materials and biology so if we can take
biology specs in terms of three-dimensional complications and
spatial and all this stuff and layering that wild you go to the very very
limited assortment reels but and do that on the engineering side with all the
much longer list of materials it suggests to me that eventually on that
plot where we have the engineering we’re slowly nudging things way or the other
that we should be able to go way to run but from for the short term looking at
the biological data what you got I could’ve but I was publicly it’s
basically being posted but I couldn’t put up some really really cool Brad’s
showing where that end is and then in plants and animals that are using
different materials collagen cellulose plants can actually push it further
animals so yeah materials yes but we do have a reception at 4:00 p.m. and the
bio OAD Lobby so if you have more questions and you’ll have an opportunity
that as well and I’d like to thank you for coming in speaking

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