Good Morning, This is Lecture No. 2 of the module futuristic topic on Robotics okay,
In this First lecture module .we studied micro Electrical systems from characteristics futuristic
topic and some technology what is name?
What it is important for and why it is gaining for?
Then some issues related to how the names based device from fabricated what are the
different fabrication fascination involved and then we had a little bit look at used
of names in robotics so in today' s class we will have some introduction on some other
unconventional names in fabrication method and their use .
In actually building the micro robots so we will have look at that and then there are
technologies where you do not have right now any applications in robotics.
But they very much potential for applications in robotics.
Okay, so these technologies will study first and then we will go on to applications in
robotics .with the technology which we have studied in the last lecture okay, So to the
base like silicon base Phillies.
Base names fabrication technologies that technology will apply some micro robots micro accelerators,
micro manipulators and we will see how this quizzes can be fabricated by using QDA fabrication
of dulcet base technologies okay So what we will study is basically is unconventional
fabrication possessives like micro studio lithography okay, I will explain you what
is this process.
And what are the important aspects of this process why it is different from your conventional
base or silicon base or dulce base fabrications and then the laser base micro motion it will
have a little bit look at this laser base micro motioning technologies okay Why it is
important again like what are this advantages in like that and then we will move on to name
space micro manipulator okay, Or application of this technologies or robotic purposes the
main important application most squarely used popular this days.
Micro manipulation okay, This micro manipulation is important for like?
Bio-cells who want to manipulate bio- cells who want to move and study their properties
the thing like that this is very important for bio applications and in bio surgery where
you want to manipulate very accurately very phsislely some location in your brain surgery
or whatever okay, In those application this micro manipulators are very important.
Okay, And then we will study one mobile micro robot this is very recent development and
but you will look at and see how like what is a domain in a micro domain how things are
From the conventional domain okay, So we will have look at that fine.
That would conclude this today's class this module will be futuristic of this robotics
okay, Then also we will have look at some other topics which are not covered in this
course but you should be aware of that they are some other topics related to futuristic
they are more futuristic kind of applications .okay, let us start with a micro schedule
What is the motivation for studying or for going this process micro schedule lithography
basically the limitations of the conventional names fabrications are like basically it has
a capability to fabricate only to dimensional micro components okay, Or plainer kind of
components you can have multiple plains?
But essentially they are plainer components you can have one level, two level, three level,
procedures for micro fabrications but they are essentially of plainer in nature okay.
So each level we will have a plainer structure okay, But you can have like multiple plain
but in many applications one may need through 3D through type of components okay, We just
doesn't have plainer laser but it is like two three dimensional nature like say for
example, You can imagine a flower pot.
Kind of a structure okay, It's a true 3D structure so how to fabricate those kind of components.
So that is a basic motivation for going for the micro studio schedule other important
motivations is basically limitation on the number of masteries that can be processed
conventional name professors okay.
Micro lithography gives like more number of masteries or more wider choices for masteries
we poses okay, You can poses hethamixe you he can poses metal powder or he can poses
polymers in micro lithography okay, Polymer and ceramic entering are very widely used
for micro lithography okay.
Now what is a idea how microstereolithography works okay, Is the idea base on the which
is rapid programming okay, So it is like you build a component there is a liquid and then
you use that liquid photopolymer it will get affected like these liquid will get affected.
Then the liquid will turn into soled when you expose it to layer okay,
So that is a photopolymer liquid okay, And then the idea is like to generate one plain
planar section on the surface of the liquid and then you have other planar section?
Built on the top of these planar section okay, So these section by section you gone building
the components okay.
So let us see how these process will look like in animation.
So but that is a basic process that you built components layer by layer.
So if you have say as for example follower pot example if you take you first dived the
soled starchier into plains Into different layers of plains okay.
And then you have each planar structure or each plain or each section build level by
So first you will have a first lower level section build on the top of that next section
will be build like that you will gone building the components level by level or layer by
So there different types of this process first are a scanning type process.
In which you scan a section by lines okay.
So you will have plain in which you will have a different lines drawn okay.
I will show you again how the scanning process works.
But you don't exposes the entire layer at a time to light okay.
You will scene one line okay, by a laser which is pointing on the surface okay.
So then you scan on next line like that you can scan the different lines then gone building
the sections okay, That is a process we will come to that again in the animation.
I will explain you that but that is a scanning where there is no exposure entire of the entire
section at a time in the dynamic mass process.
We have a mass which its changing his step dynamatically or automatimatically so in this
process is like how it changes and all we will go in to little more detail in the slides
to come but it is basically you have a mass which his changing continuously okay, so you
exposes at a time in one section okay, then change a shape of a mass and exposes the next
so like that it is a process of building components there is exposure at a time for a entire section
Again I will come to that when I will explain you detail how this process actually works.
But these are the basics to differentiate like in the scanning type process and dynamic
mass process okay, Let us the scanning proceeds in more detailed.
Okay, what you see here his laser curable photopolymer liquid which is kept in this
tank and then there is a lens which is to focus the laser light on the surface of this
photopolymer you have this zee elevator which will move this stage in to the liquid once
the one of the section is completed to that next section can be build on the top of the
section okay and then you have these mirror actually.
I have shown your one mirror but it should be two mirrors you have to scan in the both
the direction, so I the sake of simplicity I have taken only one mirror.
But you will typically have a scanning system which is similar to then what you the monitor
have, But n this case the difference is like the deflection of the laser beam their happening
because of the movement of the mirror.So we will see what are the different type of movement
we can achieve that but essentially there is a mirror.
Which is moving and then it is scanning the particular section on the surface.
Now let us see how the scanning happens again the photo polymer and elevator the elevator
is first dipped in the photo polymer and then it is brought up.
So that the particular thickness of the liquid is there on the top of the surface that is
the elevator now you want to scan one of the section, sections say is this of the shape
and now you can see how the scanning is done line by line the entire section is provide,
so this elliptical shape you wanted here is drawn line by line so, you can obviously see
there are some errors that will occur will not be an exact section.
It will be slight error because of the error but, there will be their limit the accuracy
may be 5 to 10 percent okay if you are scanning like bigger sections okay then it be much
better if you are scanning very small sections then you will have a little bit lesser accuracy
in terms of percentage okay so I mean you can see a limitations again with these because
a these kind of effects will not be able to build very, very tiny sections.
I mean very tiny micro components which are of sub micro damages is not possible okay
so this is kind of technology is use to build components in the range about like say a 30
micron onwards or 20 micron onwards okay you cannot really I mean you can go below that
but then like it will be very costly process in the first place and then I mean it will
have that accuracy problem In terms of percentage accuracy okay.
So once you do this scanning the section will be built on the surface here okay so this
shows the top view and this is the section view of the okay so now once this section
is built again the process is repeated you dip again in to the liquid photo polymer so
that the surface station effect is gone and then the photo polymer comes and the surface
of on the top of this section and then again you rigid to have a appropriate level of the
photo polymer on the surface okay, The thickness can be controlled by controlling the sea movement
or this movement of the elevator if you bring it to the top It will be lesser thick okay
Of course it will some addition like addition effect or some kind of a thin layer of the
liquid always will be there and you cannot have zero thickness or let it be some depending
upon the viscous city of the photo polymer you will have the limitation on the thickness
so you race the elevator elevator is independently controlled see all these movements this sea
direction movement of the elevator and then see scanning movements they are controlled
through computer okay.
So they are synchronized with each other and controlled through computer okay see your
laser light intensity it goes up to a certain depth only It will not go full depth i mean
so it will go up to a certain depth because the focal point or the laser focus is only
at a one particular point so up to certain depth the intensity of the light will be sufficient
to accrue the photo polymer okay so this solidification will take place.
Only in the small thin layer okay so there are these factors as we discussed affecting
the resolution of the components first is lesser intensity like how much intensity you
have then motion of the beam okay.
How fast you move the beam if you move beam very fast like you will have like lesser thickness
of the line if you move beam slowly you will have a better thickness of bigger thickness
of the line so you can control that to have accuracy good accuracy then what kind of photo
polymer you use for this purpose then what is your focusing how accurate is your focusing
or optics that you used for processing and then exposure time okay.
These are the factors on which the resolution or the accuracy of the component is will be
dependent on and then in case of syramacic material you use a ceramic powder and then
you use a laser based sintering of this product okay.
Instead of like kind of having a liquid photo polymer okay now there are several variations
like you can have fixed optics and move the tank okay in the animation.
Which we saw the tank was fixed and the mirrors where like moving so there was a the moving
laser beams okay the problem with that is that the focal point doesn't remain a see
as use tilt your focal point is changed now it is not on the surface of the liquid anymore
it will be either inside or outside the surface of the liquid so there to avoid the problem
this is one variation which people try is like you the optics fixed and move the tank
Of course we will have the sea direction movement but "X" and" Y" standing scanning we do by
moving the tank okay then there are various ways of scanning one way we saw was galvanic
scanning mirrors like rotating mirrors then like you can have linearly moving mirrors
okay so the mirrors will move in a linear fashion the advantage hear will be like the
you can have your focal point fixed level with the linearly moving mirrors okay.
Will not get in to details of a optics how we can have and all the things but it is possible
then you can have a restores scan versus vectors scan what we saw was a vectors scan okay so
whatever in the section limits are the laser beam it changing it changing's its direction
at the limit of this section.
But in a restores scan the say even if you have certain of a circular section we will
move the beam to train the rectangular section and then you will switch on and off the laser
lights at appropriate points okay. so for example if we go for the this thing for this
section I will decide the limit points for this particular line okay.
Actually the mirror will moving to take the laser beam from this point to this point like
in a rectangular fashion scanning but the laser will be switch on at this point and
switch of a this point okay so this movement from here to here is kind of a not very efficiently
So restores scan is not deferred okay vectors scan will be kind of much faster kind of process
okay there are other issues regarding like where you have velocity reversal and so it
will have wherever velocity reversal their exposure time will be more so it is again
like your how much accuracy you can sacrifice to have I mean because of like more time of
exposure you will have like little thicker sections.
There so it depends up on like the way you have designed your control system to basically
control on this parameters okay in here now this a dynamic mass process so you have this
mass his controlled by the computer which is dynamically changing you have seen these
botches with led display right so there this dynamic mass is something of that short you
have this pixels we share like other made to have dark point or to have transparent
Depending up on the pixels like weather.
It is dark or whether it is bright or it is transparent this mass will be produced okay
so say for example this is a whole of your led type of screen in which like if you want
to have to this kind of a section and you will all this all the other point will make
dark and then this part is make bright so that it is now transparent okay so that is
the kind of a philosophy in dynamic mass okay now the inherited disadvantages of this thing
is like you cannot have like a higher power of the laser for exposure.
Because it will damage this mass itself okay so you need to use a moderate powers of the
laser and then you need to expose entire section at a time in this process okay and then again
this other part of the or processor remains the same like you have this elevator here
which will load in the photo polymer tank and then will section by section he will be
the component but now this section is exposed at a time okay.
And entire section is exposed at a time till it is faster process this entire section is
getting exposed at a time if the processor is faster so you have this first section and
then like you will have second section of different size of dimensions and then you
will have the third section like that you will go on building section by section okay
so this is dynamic mass process now you can see that since here.
The section us expose at a time like and there is no line by line writing of the section
if the accuracy of the contuse of each section will be better than the scanning process okay
but you will still have in the sea direction accuracy the line as in the previous case
you was in the sea direction you will have this steps as they are you cannot do over
with that only thing you can reduce the these sections size okay.
And they maybe improve up on some accuracy in both the processes but always you will
have this stepping nature okay in the third dimension okay so this are the limitation
s that I as I mentioned this smooth 3d surfaces are difficult to fabricate stepping effect
will always be there and the mass production and this another problem or challenge that
mass production of the several components at a same time is difficult in this case because
you can have like see for that if you want to have the mass productions then you will
need to have multiple laser beams.
Working at the same time okay.
So far that is.
I mean some people have tried that I mean producing multiple section at the same time.
It is a technological change actually okay.
Then extremely small features are very defalcating to produce like we cannot go to sub micron
kind of dimension okay.
So 10, 20, micron onwards accuracy is reasonable good to achieve with these micros okay.
Now next we will go for laser micro motion okay.
We will have just a brief idea about with is laser micro motion and why it is useful
and what are the advantages things like that okay.
So what is magnesium for laser micro motioning is like you have a pluses laser beam like
you have laser beam.
But it is not expose directly it is given in the pluses okay.
Switching on and off kind of a so you will have these short pluses of the laser beam
And there in each plus there will be very high energy the livered to the material at
your prosing okay.
So these pluses they will be focused like you have a laser beam which is to be focus
on the surface which u want to machine and at the focal point like you will have these
surface so the entire energy in a very small location it gets consecrated okay.
And then the energy is delivered fashion of this process okay.
The typical a time for these first will be about micro second and nano second okay.
That kind of a process we are talking about okay. in some cases like most advances laser
which are say he as a faire that a name is a faire lasers they are giving a pluses in
a tempt second period okay. so like less ire is a period more is a cuirasses that you get
because like in a short time you are giving these high amount of energy to the Montreal
because of that like it doesn't get a changes Montreal to spread that energy okay since
delivered in a very short time there is no spread okay.
The energy and that results into very localize like effecting of the met real at your prosing
so very localize effect will be there so like shorter time more localize is the effect okay.
and because of that like more will be your corrosive of the machine more shorter will
be like a the scares at the leave age that you produce on the set face of the machine
okay. the main advantages of a laser micro machining verses the conventional machine
process are you have micro cuts on complicated two dimensional shapes.
So any complicated two dimensional shape can be in very easily off course you will need
X2 stages moments to have that shape or that symbol or arrant accuracy of the laser machining
will allow you to have very complex nature of two dimensional features cut out of there
much here okay, and then this is the mass less process there is no mass which is expensive
process just like if you want to compare.
Now with this material remover process with they have seen in conventional to dimensional
names process then this process is doesn't required mass okay, so that brings down the
past okay. then it has minimum energy in proton my that goes in to the laser might commissioning
okay, And then this is a another very important advantage is that there is a minimum damage
to the micro component.
Which is getting fabricated because the energy is very much very much localized it is not
spread on to entries surface okay, because of the local nature of the thing the area
which its getting affected around this local where ever having a cut its very short very
small area is getting affected.
Heat affected zone are the laser micro machining is much lesser okay ,and you can process the
verities of materials okay.
I will give you one example like say for you have ND YAG laser with power say 150 two 200
This has wave length of 1064 nanometers okay and his facilities fabrication of non metals
like you can presses ceramics and metals all source of metals we can presses
For example the of the steel thickness 50 to 200 microns or even little more they can
be presses like point 5mm or 500 micron up to 500 micron is a very easy to presses with
150 to 200 watt kind of inertia aciculate okay but now these since this power is consider
to be little on the higher side or moderate side so if you try to presses now the polymers
with these power or it will be difficult they will have like more effect.
I mean more kind of energy delivered they do not require that much of energy and if
you are delivering more energy than the kind of guts or kind of producer mechanizing accuracy
that will merge.
So you will able to process the but it accuracy will be poor so for that you go to exam modulation
okay these are laser mainly for processing polymer materials okay.
The metals are difficult to presses through these lasers and then this laser have wave
lengths of order 200 to 300 or 400 that order nanometers because of that you will merge
better accuracy on the surface okay so is like higher the wave length laser will be
there accuracy okay but we are talking accuracy in terms of a few nanometers or macro meters
okay for exciters lasers it will be very good or I mean from accuracy point of you okay,
were it can presses only polymer okay.
Now will see how these fabrication presses there are used for the purpose of robotics
application okay, we will have a look at these micro grippers or micromanipulators okay,
will have look at several micro actuators which can be used for future robotic applications
okay, here will see mainly the actuators which are not currently used for micro robots but
they will be they have high potential to be used for micro robotic applications okay,
and then we will see one very particular very nice design of a this mobile micro robot okay,
so it is called saturators so why it is called and all those thing we will see it ,okay.
Let us first start with micro grippers okay, now you can see here the principle here is
dependent up on the electrostatic actuation using comb drives okay, so comb drive are
basically you have these kind of comb like structure here you can see these are the teeth
mixing with another set of teeth on these part okay, when you apply voltage to these
gold conduct pads okay, then there will electrostatic force of attraction between teeth on this
side of the comb end other side of the comb end okay.
And then because of the electrostatic attraction will have these manipulator movement gripper
movement okay, that is basic principle of operation okay.
In terms of fabrication now we can see that these are freely moving structure which are
accrued at this point okay, so this is similar to the cantilever fabrication forces that
we saw okay only thing now the shape of the cantilever is different instead of the same
simple rectangular shape they have comb like structure proper ting auto care okay.
Otherwise the presses is exactly the same okay are you have like multiple options have
liver to fibrotic these multiple way in which we saw a two way in which the cantilevers
can be fabricated so you can use either of them or you can use another presses also to
have these cantilever structure in the comb shape form realized okay and then you can
do this gold conduct pads okay usually the conducts.
Which give the electrical signals to your structure okay, wherever necessary there are
made out of gold okay, but it is conductive okay.
So you will have this big pooled pads on which will have some shot of wire which will finally
connect these thing to the pin that you see out of your eyes structure okay, so inside
IC that you see conveniently, okay.
whatever pins you see outside there are connected to the point , where your actual pressuring
electrical is happening by very thin wire by presses called wire bond presses okay,
so see we seeing one end like it is the whole thing which is going inside the shape okay,
or these part like what your part you see up to these point that will be inside a chip
and what you will see outside only these part and some contacts okay, so there are the producers
this are the only the fundamental concept or structure there are many things that go
behind like for packing issues and other issues okay which we are not going into details so
these are the principle on which these micro grippers will we are there based and then
these can be fabricated by using conventional presses ,okay.
Now let us go to actuators there are different types of actuators possible advanced level
see if you thing for conventional robots what are the actuators possible electrical motors,
electromagnetic principle okay, and then may be hydraulic principle these are the two major
types of actuators which you have for conventional robots now you go for micro domain like you
have multiple possibilities like.
You have thermal actuators possible okay.
So I will explain how these basically on principle of biomatiles chip then you have piezoelectric
actuators possible then you have motors but based on electrostatic principles okay, people
have not used for memes devices a magnetic type of motors you will not see in the literature
in the magnetic motor, motor based on magnetic principle at very macro step okay, this we
are talking about the scale of like say few hundred microns okay that smaller size we
are talking okay, and then we will some cantilever type of magnetic actuators, okay.
So let us start with thermal actuators so as I said it is based on the bimetallic strip
effect see it is very easy to have multi layer kind of structure bit for with the memes technology
that we have seen okay, you have cantilever on the top of the top of the cantilever you
have one more layer and then your bimetallic strip is in place so now you have this structure
heated okay, that are multiple way like you can have localize hitting possible you can
just run some kind of a conductor on the surface of the liquid.
On the top surface of these layer and then you pass current with that you have I2R F
of hitting then okay, that is the resistive hitting and then that hit we deliver to the
structure will expand upper layer or contract or whatever depending upon what other coefficient
of thermal expansion of these two layers and then it will have these actuation possible
okay, because of the that differential coefficient of thermal expansion okay, that is the way
this thermal actuators okay, they are used for switching.
I mean currently if you see in the technology there used for switching in the sense like
you can have some mirror attach at this end okay, reflecting surface and then you want
to deflect the light from coming from one fiber to other fiber okay, so this kind of
switching between two light weather you want deflect the light or you want to or you want
to not deflect the light okay that king of thing you can achieve by using this types
of mirror based switching it is basically switching of the optical signal you know the
optical fiber there used to transmit the signal or you want to switch the signal you can use
the mirror okay, so that is current use but then see this can be used as well for the
robotic application ,okay.
Now piezoelectric effect is basically when you give there are some materials when you
give voltage to them they will expand okay, so these materials they are very compatible
very much compatible with their name base fabrication okay, you can incorporate very
easily these materials one of them is SIO 2 okay.
So these materials on the cantilever now you apply some current with these they will have
the piezoelectric and because that they will expand okay this is called the piece of patch
to apply on the surface of the cantilever and then this will bend when you will apply
the voltage in the piece of patch okay that Is the piezoelectric.
This type of actuators are all ready in place in many micromanipulation basically for something
called AFM (atomic force microscopic) okay that is very popular application this kind
of thing okay there is no I mean you can use these piezo actuation in a different ways
in micro structure I mean you can have this piezo actuation done on the substrate and
keep the cantilever keep the probing seen.
In the AFM is other way wrong you have a cantilever very micro or very thin cantilever okay which
is having a probing tip at these end that is very thin tip at the other end and you
give micro moments with the base or substrate by using piezo actuators okay so that is the
one of the application of the piezo actuators okay.
Next will this magnetic actuators it is cantilever beam type of actuation here the principle
is like you have this magnetic bead place on the top of the cantilever surface okay
then now there is a copper coil below the substrate will see how that is fabricated
will see the animation of the fabrication in a minute but there is a copper coil which
on these side on the lower side of the substrate okay when you now pass the current through
copper coil because of the magnetic field this bead will get attracted below and then
will get a that kind of attraction more the current you will have the more effect.
So let see the fabrication is done so you have the substrate which have used hippokics
substrate here then you have kind of the copper deposited okay you pattern this copper and
then produced a coil out of these okay is either coil is of these nature okay so you
pattern or you have the mask which way will produced this kind of structure on the surface
and then you exposited and do your teaching and then it will get spinner coil over here
okay if you take the section it will look like this okay.
Now on the top you again have is window open in which you will deposit whatever the cantilever
material you have okay on the top of that now you have another deposition like another
window will be open and in that you will deposit this bead okay now ones this bead is in place
then you can edge the entire material remove this part okay so and realize your cantilever
so this way your structure may of magnetic micro actuator will be getting now you will
pass the current with the coils and then you will get actuation okay.
Now these are the what we saw were all are actuators now let us see one very elegant
structure which is used to mobile robot oaky so essential you have these type of cantilever
structure which is free it is not attach to the surface.
Okay, it will look something of these slots when you see from side.
Okay, now you apply the voltage between these and they will substrate because of the electrostatic
charges here between these gape they will a electrostatic force of attraction and these
will bend down like this okay so now you increase the voltage then these part is going to be
scratch on the surface and move little further.
Okay, is part is fix since it is as a larger surface of contact and then see if you here
there is just line contact okay this part these is the surface type of contact here
and your applying more voltage more electrostatic force these as to bend little more so it can
do that by scratching the surface there is a line conduct at this point it will just
scratch on the surface and then it will move by a small amount on the surface.
Now you release the voltage okay then is will became the structure of these kind then it
will slide, slide to this part it slide little bit on these side.
Okay, so like that you do multiple times in pluses and then you will achieve the movement
this type of structures on the substance okay so this kind of a much cured kind of a mobile
robot I mean how to change the direction of the motion is the initial then how to change.
The orientation like if you want to take a turn how to do that these are the different
issues like how do you modify the structure to achieve that kind of thing there are the
issue but this is the principle or basic idea that the people have tried for that will have
there will wires connected for this contact substratum these robot this wire also will
have this own effect on the robot .okay,
These are the issues that one needs to deal with but these is a very in motive kind of
idea for mobile section or the micro robot.
Okay, so these are the two gentlemen's who tried this idea and is very recent like 2001
they have a paper initial find list.
Okay, it can made of anything actually the material they I think they used the poly silicon
Now let us see some other topics which are futuristic nature and which we have
e not going into depth of that but these are the again these are the topic.
Where, people are caring out we search so one of them is under actuated manipulator
So the essential idea here is that here you have manipulators which has numbers of degrees
of freedom more than number of actuators.
Okay, typically these kind of problem like for example you have these or conversely like
the example that we are looking at we were looking at these throughout is force this
2D or 2D of freedom to degree of freedom manipulator is 2R manipulator now you attach one more
link at these end these is the link is attach but there is no motor which is actuating these
okay now the problem is like how do you control other two motor such that these link goes
from say for example these decide position initial position to some other desired position
okay say for example.
If you have this in horizontal place okay no gravity effects how do you do that okay
these kinds of like are mainly related to control to under actuators manipulators a
controller is a big issue in such manipulators if we have seen for some BD control kind of
places okay so here you will need very completed control logarithm which will drag this link
from one position to other position in the specific manner.
So like we have actually that manipulator in one of our lap and some research is going
on that manipulator in this direction.
How to do this control okay now other thing to other point to mention about this under
actuator systems like this is the big domain actual if you see under actuator manipulators
or under actuator system is a big domain of system the very simple example is the your
aircraft it has number of degrees of freedom more than the number of controller surfaces
Which it is operated okay so that technology the problem is in the aircraft there are similar
to problems in the under actuators and typically for tackling these kind of systems you will
need good amount of physical understanding are physical inside so, What is happening
in the system okay in the system behavior so that kind of understanding you should have
very good understand of that kind so that like series developer good controllers to
control these okay then you have seen these example.
Already is a legged robot okay you have seen one of the example of natural which is six
legged robot and then in that in legged robot you have possibilities like you have a running
robot or hopping robot so if you have single leg it will be a hopping kind of something
it will just bum or bounce as to stabiles itself and then if change the direction of
the link on which it is copying then it will start moving in a particular direction okay
if it is vertical it will just bump under same point in place it will not move but if
you move little bit it is start moving in a direction which are posed to that okay.
So that is the very much studied I mean that people have like over the ears developed many
different types of hopping robots and many different strategies to control the hopping
robot so these is typical dynamic in nature like all these they are continuously moving
so it is not that is have fix position that they will achieve okay so they are continuously
in the dynamic equilibrium so you can go from one equilibrium to the another dynamic equilibrium
okay so it hopping at this place.
Now I want to hop at some other place so how do I move it from this place to go to that
place but I can do that but it will be always in dynamic equilibrium at the final position
also it will not be kind of stopped it will be have a dynamic equilibrium at that point
so that is the main difference from in the point of view of control in what we have seen
what control we have seen what is this type of strategy, okay.
Next is under water robot like if you have robot for under water application okay so
there are similar in nature technologically to aircraft kind of structure we will have
control surfaces we have a propellers we will propeller them in their bolder and then you
like problem is to control the surfaces is that you achieve particular a propeller motion
are particular it goes to a particular place something like that okay.
And then in addition to that you have to control the binary so that it moves with respect to
the water level okay it goes deeper and towards the surfaces if that there is a different
mechanism used to have that kind of motion possible okay, then you have which are against
to aircraft but smaller in structure there are many technology issues regarding what
kind of lifting force you will have nothing like so that is again technology change right
and then converting this flying robots into a autonomies flying robot is there okay, these
are the other futuristic issue robotic area okay, so will conclude these selection.
Of what were seen is basically micro phycrpy these are based micro version okay these are
the presses for like fabricating micro compounds but it are based on the unconventional kind
of presses okay then we saw some micro grippers and manipulators then one example of walking
micro robot and then couple of micro actuators okay and then some other futuristic topic,
These will conclude this lecture and then with this I think we are concluding the entire
course okay fine these case studies model will have all ready seen in the previous may
be will have some more case studies okay, fine.