I'm Devon Brown on staff here at I.E.

and and be introducing our
speaker today substituting for

David got feet who is traveling
to Seattle for the the N.C.I.

annual meeting that's being held
at University of Washington.

So our next nanotech will
be two weeks from today and

that talk will be
Surendra Czaban from Capsis and

that talk will be on current and
future cell therapies for

treatment of type one diabetes so
that's the next nanotech That's coming up.

But today I have the pleasure of
introducing Dr Michael Veron Burke

who is assistant professor here in
mechanical engineering at Georgia Tech.

Prior to.

Georgia Tech he was assistant professor.

Technion Israel Institute
of Technology and

also he has held the position as
a researcher in evolutionary biomaterials

at Max Planck Institute for
metals research so

today he has a really interesting talk and

the title is a biologics and try to
biology He says even fictional address of

the last Eric is a lost
American surfaces so please.

Welcome Dr Varian.

OK to everyone so.

Few years of evolution have led to a.

Biological systems that can so
as a source of inspiration.

Really.

Which is the science of technology for
the rocking services so.

We can.

It is possible to look at the surfaces
that are found in the different

attachments rock shows in malls and we
can there are the NIEs there are several

structures that can be associated
with two main groups the group one is

shown here that is associated with
a smooth surface that there are.

Occasional.

Three frog.

If you find something like these so.

Certain structures that help
us to grasp things well so

one group is a small
service as there is also

in the other group that is based on the
higher e micro structures that are shown.

In the these slides and
these services process heris that

terminate at the with field feel the theme
field throughout China so for different.

Sizes and examples that you see here
are for being told fly spider there and.

So we can learn a lot from this structure
is the question is how and in principle or

thinking about the questions that need to
be answered that when working with this

surface is first of all we should think
about what are the mechanisms that he them

that he will behind the effective
performance of these structures and

whether it is possible to
abstract these structures and

to build something similar
based on the simple engineering

engineering materials to use it for
technical applications.

You don't have to answer these questions
we need to know how to model biological

surfaces using engineering materials and
also how to test them at the cuartel.

In order to measure
a force that the generated

in in between surfaces first of
all I would like to talk about.

These more simple questions and

then I will give you several examples
of what we did in this direction

in finding how to mimic the surfaces and
what they can be used for.

So in order to more though biological or
surfaces we lost

the merits which able to recover
from large deformations and

also able to dissipate McCain just so
the result of.

Good correspondence between biological
very complex structures and

simple textures that
can be made from from.

From official materials to
materials that we usually

use Pedia mass wanted me
to look sun which is a.

Rubber like material that cross links
with several of the temperature

that is a little bit higher than the room
temperature and one of the new still works

on that which is also rather
like material that is used by.

Dental walks to court be what it will
have in our offices in order to make

prostate sick.

And this material a problem arises within
really really short time five minute that

the room temperature now
that we used to build this

structure is some based on the soft for
the lethal graffiti which is a raging.

For the resists layer on top of silicone
the way for and then the pouring.

Busy a mess for instance that cross
links in contact with this template and

then it can be peeled and the used for
different experiments and

the way also uses a metal greeds prepared
on the thin sheet metal that is.

That is.

That.

There's a certain greeds that
are created by lasers that have

through opening and
then they again we can use.

That that sort of if I really slow.

Relatively fast and then before
they get to the other side of this

metal greed they the.

Only fight we can then feel them off and

they use it in different experiments
now their operatives that would be able

to test this structure is
a strong schematically here so

it consists of two main units you
need number one is use the four for

displacement so
it is consists of three stages and

on these three stages we fix
mating call interface which is.

Usually made from.

Material that has one the rod the rigidity
of freedom which holds to adjust to so for

a lot when it comes to contact with its
counter face the other same ball that is.

Cast from either of the two
mirrors that the walk with

it is fixed to a measuring
lever that consists of to.

Force sensors that help us
to measure a normal force so

when the mating surfaces brought on
contact with the same pole a normal force

gauge is law that in that we can control
the normal log when the same pull these

drugs are a little to the contact plane
we can measure friction of forces by.

The lising deflection of
the sensor This device is.

To be very small it and it can be feet
into the Vulcan chambre of electron of

scanning electron microscope because it is
good to measure forces that are generated

by different structures but the way also
needed to see what this force is due to.

New structures that would be and this is
one of the recent examples of the surface

texture that is a law that in the normal
direction when this force when this.

Up our offices assembled outside
they Sam we can place it

under the optic microscope in order to
see through all that there on spot on.

Through the spot on the substrate
what is the real current that air and

how it evolves in response to
different forces that we apply to

structures which is extremely important
in trying to understand how with

their weights now this is.

A fourth of the device these.

Yellow.

Dangles represent four sensors that help
us to measure forces junior rated here at

the interface between two same balls
that are not really well seated and

they saw this stages that help to
move one of the same balls and

all through their actions
the device is assembled.

On the cover of the C.M.
and this is the into which it can be

it can be pushed and
to be operated inside so

just part of my talk will consist
of discussing how we can.

Feel feel feel feel gentlemen also
on the ends of these Harris and

what we can learn from them.

So looking at these staying in
Harris that are found in different

animals that they evolved
independently we can see astonishingly

similar Jorma do when we compare them.

To give it so
this film films found on the attachment

of hair as in the beetle fly spider and
the get go and

you can see that they all look
very similar they all rate like.

Things feel.

And you can think about duct tape that
you peel to your touch tool to table for

instance and if you pull it in different
directions it will respond differently so

this is their idea that is employed in.

These structures it is possible to explain

it based on candle model that is
committed to going to hear of so

if this is the duct tape that I just
mentioned the force that you need to

apply you know that from the surface will
depend on three part I mean there is one

on that angle if you peel it if you try
to pull it in the direction of the film

it will hold well if you will
peel it in opposite direction.

Detach very easy to do so

angle is important the second parameter is
of course chemistry of the interface and

it also depends on the weaves of these
Feel so the contact area is not really

important what is important is the wave of
this field that their minds the force and

these laws to use their variable surface
area in the much more efficient way

if we split the large quantity
into a large number of

small films and then the force that
we need to our plane order to detach

the whole structure from the surface will
a proportional to the top hole we have

two of the total length of
all with some together so

this is their idea and we want to test
it in or at least to verify that.

These.

Is correct based on measurements
of real Any most and.

Results that they represent
total feeling like line length

the sum of fall silent sum
of all contact elements.

In about twenty different animals to
represent it as a function of their body

mass you can see here that boys
you must ranges within the more

than four of those are from are going
to hew wood from server roll micrograms

from my it's to over one hundred grams for
get core and total peeling a line

ranges within eight orders of magnitude
from several micrometeorites for

my it's to over one kilometer for
get caught and

clearly you can see that there
exists a good correlation

between these two parameters so
we wanted to.

Employ these Sadia and
we had to find their way how

to create this structure
as with this field base.

Texture that will enable us
to test whether it will walk

in artificial surfaces so
technical solutions to

overcome several problems which
are increasing the peeling the line

length without walking away
with a large number of these

projections which is not very
easy to make them so we we solve

it by suggesting working with
the longer wall shaped structures.

Ease of template.

Through release we achieve this
by working with projections that

roughly pippins equal to this office and
we also had to secure gradients and

projection with which is brought
parity that is associated with.

Harris that are found in different
emails so the solution schematic

a presentation of the solution can be seen
here so will shape the projections that.

It's a deep thought and
has a flexible clips that can do for

easily when they come in contact with the.

Interface So we found.

When you.

When you that it was able to create any.

Openings within.

This two examples hall inside the hall and

through floor within the blind range and

this is an example of one of
the fields through aisles of.

The projection of the surface truck
sure that they were created based on

this principle.

Now also for.

Micro structures that were created
recently so this is what we have now and

example of image of banks
than templates that.

It is laser machined to have structureless
that they use there's a template in

curing the this is an image of
the projections that were created from

even use look some cost against this
template and this is Sam images of.

Projections having different heights and
this is a short video that.

Represents how they structure is operate
when they logged it in normal and then in.

Direction to OP was a sight so

we can see how these structures
can invert themselves and.

Themselves brought purely to.

Their face so
you know that to test their operation we.

Focused on.

Verifying that they are that pulling
angle is indeed important but I meter so

we design the test in the which the
surfaces swore Lord that normally these.

Way until a certain a very light load was
achieved and then the way I applied the.

Displacement to.

A lie in the oldest structure is in
the same direction this is the result of

force measurement friction force
are present at the displacement.

Bleck lie in the represents through
force and great ally in the.

Normal force so when the displacement is
applied the surfaces initiated you for

an elastic and then they start to slide
this is the point of slide you conception

this is the point where surfaces of a so
on and aligned together now.

Actually we wanted to test the pool
of forests when they surface as

started to be started to be
withdrawn from each other in

different points and
this is a schematic representation so

after a certain displacement is applied
we start pulling our counter for

different angles and measure of the forces
that the junior weight at this moment so

in the represents the force of the
generated at the time of the pulling and

the gray line represents the normal
component saw the lowest

point of actually gives us the pull of
force the force needed to be generated

in order to detach surfaces
from each other and

these are this is the summary of
all the tests that we that we made

to study pulling angle they fit the
bullying deliberately made displacement so

color of here represents normal force and

it can be clearly seen that
there is an optimal for

the pulling angle and for
the preliminary displacement which.

Suggests or proves that indeed
the surfaces can be used.

In.

In adjustable way saw
the pull force can be

efficiently changed when pulling the
service a different directions when angles

are large detaches with zero force
with when angles ranges within.

Seventy two one hundred
degrees then the force.

For the generated achieves Mark Simone.

Very was and also found that.

The best results are achieved
when preliminary displacement.

Equal to half the distance needed
to start sliding so some way here

which can be explained in the following
way when the preliminary displacement is

not large enough then all these
projections are not aligned well and

they do not perform more efficiently when.

Really near displacement is
very higher than sliding starts

which means that each of
the structure starts sliding.

And sliding and they all stressed
to a different extent which again

the results in the not uniform
not if you should performance

however somewhere in between there is
an optimum range when the force is.

In other topic that we started with
this structure as was the effect of

contact splitting it is accepted to think
that splitting a large quantity into

smaller structures.

To withstand.

Detrimental effects associated with
increasing in the roughness So

we wanted to test the correlation
between contact splitting and

roughness of the substrate so
we prepared actually we use the same.

Micro structures and cut them with.

Blades.

To have.

Longer Wallsten to much shorter sections
and we tested them against twelve or

so different substrates having various.

Roughness what you see here
is the same images of.

A projection some contact with.

With different substrates and
this is the result so we can indeed to see

that when we have a small sort of force
then pool of force is not affected

by a by contacts breeding
saw longer walls of pureed

the same way as they say is the walls
cut in short the sections but

when the roughness starts increasing
we can clearly see that poor force

drops quite fast and
when we have a structure that splits into

sections then this police service
is able to do with distended or

mental effects associated with roughness
too much more in a much more efficient way

you know what you see here is
the result of measurement of friction

against several rough
substrates first of all

we can see that increasing the roughness
results since you can reason for

action forces which is expected and
we can also see that friction or

force as measured with structure
with microstructure is

extremely high with a ratio
of friction to normal log

of over one hundred you can see it here
for Lords of two or three meter you don't

get friction force of about five
hundred million units which is very.

Efficient.

And larger friction forces
that may find that.

In different fields.

And this is just one example of possible.

Beacon drop process is associated with for
instance handling the way for in.

Semiconductor industry
usually it is made based.

On.

Suction the vacuum systems that
require sealing and quite.

Installation of the system so using.

Get call like micro structures can
make it probably much more efficient

but this is a question of future so
far we didn't have.

We didn't have a new
collaboration in this respect.

The second example that I would like to.

RIP to present here eases.

Is related to working with this move
a small first structures especially with.

Textures found in.

Three forms.

Looking at this three A most you can
clear recognize that they belong

to a totally different group that there
is not much common in between However

if you look at their
contact forces we find

great similarity between them
all of all of all of this.

Excitement only shape shaped projections

that evolved in the response
to interaction between.

Tall and the substrate so
the question that we head to ask ourselves

fellows was what was the reason
that led to appearance of similar

structures in different animals and
thinking about the.

Conditions in which.

This structure of operate we can
see two different things one.

The same oath can seek to very sick
certain examples of a hand surfaces and

the second all three of
them killed can jump so

high friction forces result and
given that all.

This textures process some lubrication
layer it is important that clearly.

Is known to reduce friction so we had
to find out whether the structure of

these structures evolved in order to do
to fight friction oriented problems or.

To improve.

Attachment So the.

What is this was that this
texture is a lesion or ranted and

the explanation for this is surely here
there is a contact splitting principle

that defined the round jelly years ago so
that saying

that if if we sprayed large conduct into

small sub contacts if the contact
area remains the same but

number of contact increases it
should it should lead to higher or

the Asian force and
the second report this is

was that the texture is fictional rendered
which is associated to the presence of

lubrication layer even if you
think what can happen the with.

Surface grip when when
surfaces that come in

contact are separated by a lubricant
play or you can look at this car that.

Hydroplaning loses direction with with
the road so probably these channels that

are found in between the exceptional
projections are needed in order to

drain the contacts to
remove liquids out of the.

Office.

So in order to test both people
there is this one we had to Kuwait

just to break this structures and this is
schematic a presentation of HICKS I've got

gnarly shaped projections
that we cross from different

materials who walked with the Bolivian
work song and be G.M.'s this is schematic

with three part of me that was
that important high and size.

And this is a C.M. that.

Structures and it would cost
the same to have a different.

Aspect ratios or density as Heights and.

Sizes Beirut so we arranged all
our meters in order to see how.

They operate so first of all we
that we tested their attachment

ability in order to verify these
contacts bleeding principle and

it appears that that is wrong so.

What you see here are poor forces
represented as a function of

the number of contacts when we have more.

On the surface while the contact area was
the same in both cases this is lubricated

conduct this is the right contact
you can clearly see that despite

the number of surface projections
increases by about two orders of

magnitude we have the same pool of forces
in both the right and the brigade contact

which means that the contacts bleeding
broad principle doesn't work here so

all we turned our attention to
frequently they just send with us that

the structures in both lubricate it
the right conditions so this is the result

of friction force as measured in texture
than textured surfaces in labor.

That conditions of.

More or less identical or
similar to real world

application so we can clearly see that
the surface that was not textured and

we always use some reference.

Surfaces that didn't
have these projections so

not textured surfaces has shown
very a lot of frictional force

while textured surfaces clearly
demonstrate that as the structured surface

slides against the surface against
the substrate friction force

starts to increase and
we can see the same.

Images of the frog that jumped on the on
the three If we zoom in the region of.

The interface between the door and
the three we can see the race of

initial sliding which means in Usually
there is a lot of lubricant that

the interface during the sliding
it is it is squeezed out until

the is able to get a good grasp and
sit on the surface.

We were really surprised to see
very interesting results in seeing

dry slicing condition so what do you
see here or is the performance of.

Smooth surface sliding against.

The substrate and we can clearly
observe days here sticks leap.

Motion which.

Can be explained in the following way
when we have a rigid surface that

slides against their last summer which
cannot really slide in an accepted

way the surface even behind the contact
is intention on the surface and

front of the contact is in compression so
with buckles and

then a small wave is created
in front of the rounds.

In the between two surfaces.

Relaxation and surface actually
moves not as a result of sliding but

as a result of the displacement
that the interface so

this is how smooth surface the rates and
surprisingly textured surface.

This same post with.

Appearance sliding.

In this move to wait another
two weeks play in this behavior

we would create we develop this
story more dull that in the very

simple way to explain that
the reason is that you stick.

Violence in in broad purchase of
the services that come and go and so

what you see here is.

Boise That is.

Placed on the moving there and
this muscle is the block is connected with

spring to the wall then the three
parameters that we change here.

Springs to from this.

And kinetic sick freak.

Interface So when when the conveyor
starts moving then the block actually

sits on the surface that you just touch it
fiction movies together with the block and

this bring is loaded when the elastics
rests when the last tick force.

Achieves a certain.

Value it becomes larger than
this starts it Friesian and

the block moves back until.

Kinetic friction is achieved and
then the process is repeated again so.

This was this were unusual conditions and

we started to believe this block
into a large amount of small.

Of small rocks while the total
Stephen the sun forces in some

remained the same so the interesting thing
when there was pretty large surface and

to too small a surface if.

There is.

An and this in both borders.

If the properties have the same.

Values then they actually
friction force behaves

saluted the same way however if we
enjoyed use some statistical environs and

all three properties then
difference of starts to be seen

friction force shown as a function
of displacement appears to have

some fluctuations that resemble.

More natural behavior of the surface
that come in contact and so

this is what is what is what was up
there in for just two elements if we

increase the number of elements then
these are the results obtained for

fifty small blogs or
five thousand clearly this lighting.

Becomes much more smoothly and
we do not see this like.

Soul doth like behavior
do you see moving or

first last and most and the interesting
thing is that when Green is.

Very then actually friction force

has to be similar to
the result that we see in the.

Bravest slide the so.

Very simple model doing more
though allows us to explain

the differences between surfaces that
process different number of elements

if this elements have some
variance in their properties so

we were also interested to see they
affect different geometry by meters and

I mean that we walk with
War era density and

aspect ratio this figure represents

friction force as a function of lateral
displacement and you can see in red the.

Behavior of smooth surface
that elso shows very prone on

sticks Lee behavior and
blue lines are present.

Behavior or for structured surfaces and
clearly we can see that it is possible

to change the forces within the wide
range so we wanted to know.

What is the main power meter
that our minds are just.

So what you see here is the friction force
there presented as a function of area

density the area covered by
the over the top apparent area and.

We can see that actually air density
doesn't affect friction force and

this is two images from I.C.M.

that suggest some explanation so
when we have a different area.

Then city of the projections having
the same aspect ratio clearly.

The normal or the is the same in
both cases which leads to higher

deformation when we have
less elements in contact and

they sealed it as a result of sure.

Sure Lord and then actually that area in
contact and both of the cases is a more or

less the same due to the same normal
law that is applied in or when.

They sting the property and
when that doesn't change

obviously this results in the same
friction force when looking

at the effect of aspect ratio here
we start seeing some results and

clearly some optimum can be observed
again it can be explained the base the.

Geometry of different on the images
of different surface projections here

when the they or when they
are high carb to rise by different

stiffness and when the sheerest
presses applied they bend to

a different extent the surface is
that a very real all keep their.

Area in contact while their projections
that are very high they bend and fall.

And fall on or on sides so
in both of these cases contact

area can be quite large so frequent
measured friction will be high and

somewhere in the middle
there exist several.

German tourists when they see from this
of this projections is not large and

not low and they not fall aside
they're not able to maintain

the initial shape they just stand
on the corner which results.

When possible and

we can see it here so it was found
that aspect ratio is the main power

meter that that our minds system response.

And case.

Projections were also started
thinking about possible.

That.

Really beating was found in safety.

So if you'll think about this device
you can recognize that it consists of

three different elements we have here a
blade that caught the hair we have here a.

Rubber.

That is used to this keenly
if you remember when we shave

ourselves before these products
come to market with one hand.

Or with the other hand
do we remove the here so

they introduced this element
that required us to have.

And the result so relieving unit
makes us feeling please I'm.

Shaving here us the interesting
thing is that this element actually

stands in the condition of hydroplaning
because we apply shaving form

in order to wake the shaving
broads with easier but

this shaving form creates
a lubricant layer here so

the reaching the skin stretching is
not really so we thought that this

region is a good place where we can test
our hexagonal texture they surface and

we proceed in these in
this direction now how

we were sure that is important here if
you look at the evolution of say for

Tyrannosaurus you can clearly
see that the number of.

Why.

That the found in these threatening unit
is proportional to the number of blades

when the generic just came to
the market with their Sensor Excel

they had only two blades and
they have five Y.

forests the next one had three blades and

not in the why of why porous and
what we have now.

Rates based on the five blades and
fifteen Y.

Pers meaning that roughly saying

each blade requires free
wiper to have sufficient.

Skin to reach.

Sufficient So we wanted to test our.

Rate in these units so we.

We modified real safety to.

We remove the blades in.

Relieving units and left only.

Three elements there's a schematic
a presentation of the device that we that

we use to test the idea this is
not cutting machine this is just.

A device that helps to hold save
to resort to real save to resort

as the one shown here with all.

Elements that we didn't didn't
want to test removed we

test the freak show of skin straighter
against the of this human skin

the inner surface of the fore arm
in the presence of shaving for

so what do we apply the law that it was
more or less similar to the one that

is applied when we when we shave and there
frictional force was measured with a for

some sort of that moved
with respect to to the him.

And these are the results that we obtained
trust of all this as a comparison of.

By made sixth rupture and
a real wipe found in saved to the.

Deck of a commercially available and this
is a characteristic example of friction

force measured as a function of
displacement C stands for commercial B.

stands for by the meter so.

A structure was able to generate for.

Certain force when this is
the core of this point it resents

the instant of the onset of
status lighting while tasting

by magic surface in the same conditions
this is the result that we have obtained

it was able to generate
about two times friction of.

What we use in the real
life safety results and

this is the summary of all the results
with friction Kleefisch and

they represent that there is a function
of surface texture and so we have here.

Skins three elements.

By that blade from
the original materials but

we had to cost similar structures from the
same material because the idea was to test

the effect of the geometry and not
the effect of the material so we created.

This same geometry based on.

Material by just molding grating thin
blades against the original surface and

then casting these structures
made from our materials and

what we can learn from here is that for
instance shriek shows the same friction.

As a smooth surface so there is.

No improvement due to surface
structure of the cell.

Performed illegal be better but it should.

Similar results as the war matrix surface
texture that we had while the best.

Biometric structures performed really.

Significantly better than but then.

Skimmed through agers that used
to know where days everywhere so

after this work was
published it came to us

the question the way that we can
collaborate on this topic so

we send it to them structure us
they tested them in there and

eventually they told us that
they're not interested which was

sort of strange to me and
when I started thinking about this topic I

came to the conclusion that
the problem was associated with this.

These devices safe Tyrannosaurus
are just signs to have.

Designed to become obsolete because
they want to sell them again and

again so
they don't want them to walk too well and

this is the explanation so
what you see here is an image of the.

Safe to run it say is that roughly
saying one cartridge quote will last for

one month which is not C.

really a logical cause them weighed from
the blades are made from high speed steel.

And they're called the with
diamond like courting so

they should be extremely where
we stand it is very strange

that just within one month of
using against human hair or

the where or so that they can to be used
and probably this is the experience of

most of you these devices do not
hold more than just one month now.

And what is the reason.

Now this is the schematic.

These are the blades that
actually do the walk and

this is a schematic a presentation of the
Skins to reaching an amount that needs to

have high friction now so we have high
friction here which is required and

we have low freq ssion
here because these new.

Second.

As they call it guides is
a cover of the by brick ation

layers sort of gender that that
generates floor friction and

then the device separates However
what happens after about a month

while when this layer is
removed then we have.

High friction here action here skin is not
raged in between these two guides and.

The blades start cutting
skin that creates wavy shape

and off and actually this was a very

interesting conclusion so
in that time I had saved two rounds or

that I was about to throw out
because it didn't work well so

I took it to the lab under the microscope
and I was amazed to see that the blades of

all like you saw they could steal well but

the device was not not functional rated so
what I did I removed the.

Second element that created
on the wrong side and

the miracle of the device started to walk.

Properly Since then I do
these three little so

each time I start a new save to resort and

it appears that they walk about
six times longer after this mall.

Or pure Asian and
in other very interesting result is that

I stopped cutting myself because
beforehand every other week I every other

day I cut myself probably due to that
this friction was still too high since I.

Remove the element from real safety.

I can do it much more safe and small.

Description of how this can be done.

Really simple what you need is just
a safety pin that you have to stick

from the back of the safe to resort and
then this.

Relieving unit comes out really easily so

this is not true this is
relieving you need for

them right because this is a golden brings
them golden eggs because we pay sixty.

More than we should so

after it is removed this is what
we have and this saves to us or.

Really well recommended.

And this is more or
less also summarize it we walked away

wall shaped micro structures that able
to demonstrate direction of young and

around to surface roughness and
a bill to generate friction we.

Really high and
hexagon all surface textures

to prevent either playing when the brigade
conditions they able to eliminate stick

sleep disturbances that are very rigid
to a mental cause they cause a noise.

Energy losses.

Problems with the curacy and
where in various devices and

they're using exceptional surface texture
We can also tune friction within quite

a wide range and
I would like to think all those who

helped spawn it inspired to me and
helped to run all these.

Tests and of course.

That participated in finding these long.

You know research.

And thank you for coming here.

That's it.

But.

If we have.

So few structures that should
be carved terrorized by flat top

then we use B D M S and
we cost them against so

forth that it's not going to feel
prepared structures when we walk or we.

Project chance that that.

Come in contact with the very circle
services and it is not important what we

have at the bottom then we use templates
that have through all paintings and

then we use B.B.'s which enables us
which actually sort of defies fast

before the mayor gets to the other side so
it is a matter

of speed if it wants to cross that fast we
use previous first speed is not important.

When we use.

When speed is not important.

We use.

Yes young small though so for

these two materials very similar
about two megabytes culls also.

Well these structures are quite large to
be or pureed to together with cells in

the principle they can be used in contact
with biological tissues so know that.

The surface projections for
war are involved in.

Creating devices that to move
inside they just see if the rock

causes a from a different type of
bizarrely ization the reason need for

a device that can move inside our
borders so yes it can be used.

In contact with the biological teachers.

So.

We're.

Very.

Much longer.

Here.

If this is associated with that you
need to drain you need to remove

the shaving form in this example from
the interface and it takes time.

So we're actually here it
is able to remove more are.

Lubricant and obviously it takes more time
you can see that slopes here are more or

less the same so the rate of flow
back on to remove all is similar but

this structure of the curve
more cup ability to removing.

To move you more efficient.

OK.

Well well first of all lizards have dry
systems so they don't have fluid fluid.

Hair like structures found in
the course they are the right so

liquids are present in frogs.

And.

I think that its purpose is to.

Generate attachment so they attach
themselves to you to be Larry effects.

So that's why they need liquid but you
know to to grasp things and to jump but

they need to have not that much
liquid at the interface so

they need liquid but they need to
be able to adjust its amount so

that's why they need these
channels that help to drain

lubrication out of the contact and
generate height generate high friction.

So texturing for high freq liquid for

higher diesel or
maybe not high vision but.

Some gain in the.