 We will now look at another case study, I mean we are looking at 3D micro printing as your case study thing, we look at a different technology in 3D micro printing now. So, what we have seen is stereotography based micro printing in the last case study. Here we are talking about some different technology, but using similar kind of a mechatronics for the systems ok. So, we will do that now ok. So, let us get started with these. So, if you see what we produced in the last study micro printing technology is this components which are having this layered kind of a structures ok. So, these are at a micro scale, see this is a 1 mm kind of a distance here. So, in such a small kind of a distance you can print now various kind of components here ok, but you can see that the slanted surfaces will have this step stepping effect. This is because we are stepping in the z direction every time ok. So, the stepping in z direction is the characteristics of this all these micro printing methods or the methods which are currently there in the market for 3D printing, most of them also are dependent upon layer by layer kind of a fabrication. So, we thought we will do something different about it and then we started thinking that ok what if we what if we produce this components such that the photopolymer vat here has no layer ok. So, that means this is a complete volume here, complete volume production volume of the photopolymer is there and then we are and then we are focusing the laser beam on the photopolymer and the focus is matching with the bottom side of the substrate, there is a glass substrate and the component is getting fabricated upside down inside this glass inside this photopolymer vat on the glass substrate ok. So, now if this is so what will happen ok, if you can imagine like this laser light which is getting focused on the bottom substrate is going to form which starts photopolymerizing indefinitely in the downward direction, will it continue forever those are kind of issues that we will have to see. And what if we start moving this laser beam when it is getting photopolymerized, it is when the resin vat here is getting photopolymerized ok. So, while it is focused on the bottom surface, if we scan it further then it will form this kind of a wall ok. So, this wall is getting formed and if I want some shape to be given to the wall ok. Normally if I do not change anything in the system, I just focus the laser beam, it starts penetrating down and I scan it in one direction, it will form some kind of a rectangular wall. If I want to change the shape of this wall, then I just like I have some acoustic optic modulator to change the intensity of the laser beam. So, then I use that as we saw in the last presentation, there is a acoustic optic modulator is a switch, but it can have also possibility of changing the intensity of laser beam ok. So, when we change the intensity of the laser beam, we can start forming the shape to that wall ok. And that is how one can have a fabrication, where now the stepping effect is little lesser than before also of course, when you go for the next scan, there will be some kind of a small stepping effect, but now that stepping effect will be much lesser than what we will have in the in the z direction, because z direction stepping effect is governed by the liquid layer thickness ok. But here now there is no restriction of the liquid layer thickness kind of, we are fabricating this entire volume of the liquid here ok. So, that is a difference that will happen in this process. Now, if you see the mechatronics of this is again similar kind of a mechatronics that we will have to we will be using here. So, let us say the scanning system now is same as what we had before also, but now the technology is little different. We are not doing anything layer by layer now, what is happening is when this is getting scanned, you start for fabricating some something below the focal plane ok. So, below the substrate you get some formation happening here and there is no constraint for the beam to stop fabricating ok. As much it can penetrate, it can fabricate ok. So, this kind of a way of doing things is going to produce some interesting kind of a components that we will show ok. So, only thing difference here is the technology and now how do we move these laser beams in the same kind of accuracy fashion is by using again you know the compliant mechanisms in this case also ok. So, build compliant mechanisms around this technology then like now build your now tank will be different z stage is not there in this case at all. So, z stage we can remove and then there is no tank, there is the tank is different the tank is filled with the liquid photopolymer and on the top there is a substrate glass ok and at the bottom side of the substrate you are going to get component fabricated ok. So, we will see how this is put together now here and we will look at this video ok. So, this again we are using the same laser all other things are same. So, here is a here coherent like the laser is there, it is we steer by some optics and then it will be falling here on this system setup and then you are going to kind of have the fabrication done by using some kind of a motion of this x y stages in the compliant mechanism kind of a way. And then there is this observer the camera through which you can observe how things are getting fabricated and things like that ok. So, let us see that you can see these are like components which are fabricated with stepping effect in the previous technology and as well like you know this technology as I explained will be of help here ok. So, you can see the system here and the system this is a laser control panel then you have say suppose this is a component that you want to fabricate then there is again some kind of a MATLAB program that is written to get that slices done and laser intensity mapping done all these things are done in the software and then you have you put together all these in the system this is a disk space controller then there are these voice coil amplifiers, these are power supplies and all these things are operating this system here. The voice coils are there inside and then this is a z stage. Now this z stage is stationary here there is only some small adjustment if you want to do for focusing purposes the z stage will be moved otherwise it is going to be completely stationary ok and the beam is coming and falling on the stage like that ok. So, this is how it shows how this stage is moving. So, you see that this operation happens here without any noise ok there is no friction no lubrication required and there is no noise in the system as well ok because of no friction ok and it is very silent operation you will find these stages are operating is a claustrophic modulator unit here the laser comes out of this and it falls goes through this claustrophic modulator and then falls on this mirror system steering mirror system and then finally the moving mirrors it goes to do through the pinhole ok and that is how things work here and it comes out of this small lens here and it gets focus on the bottom of the side of the substrate and here it is what you are seeing here it is scanning now you cannot see the substrate is also transparent and then the photopolymer is also transparent and you can finally see only the component that is getting fabricated ok. So, these are like micro needle like patches structures you can be fabricated very very easily by using this poly lithography system ok. So, you can see some more kind of components fabricated here where you have this needle like structures getting fabricated very very easily and there is some kind of a typical nature that you will see here you see there is some kind of a necking happening here and then again bulging and necking and again bulging and necking that kind of a formations are happening ok and there is some reason for that ok we explore this in the in the mathematical way by studying it is modeling ok modeling of this phenomena ok I will show you some results about that ok. So, from mechatronics perspective what we need to control is like ok if the laser comes at one spot how long it can stay there ok that is one kind of a control that laser if it is staying longer time then this penetration will happen to more depth and you will have this longer and longer needles coming up also the needles will increase in their width at the bottom and if you want very tiny needles you just do this like you go to some spot and and get this laser focused only for short duration and then you will get a smaller needle ok. So, like that you get a very good control over the size of the needles that you get out of this process ok and this will be very useful for generating the micro needle patches that usually are now nowadays used for drug delivery into human system instead of like you have big needle pricking your skin these needles which are very tiny they you do not feel that they are pricking ok, but it is still the drug can be delivered through these needles which is by coating the drug outside these needles that is it you do not need to be the needle to be hollow in many cases ok. So, these are when we start scanning you get this kind of a you know very smooth changing patterns and the stepping effect you can see in the in the in the y direction still there is a small stepping effect, but it is quite less here and then there are more kind of a finer observations that ok if we increase the intensity the same kind of a speed this, but the pattern does not repeat itself ok the pattern is completely different here than here. So, then we starting investigating into these details and then we make use of all the sensors to sense the data and you know start finding out ok what is the reason for such a kind of a behavior and you know that that investigation leads us to some kind of a research findings ok that is how typically the research goes ok. So, typically there is a law that is governing the penetration of the system called beer Lambert's law and beer but beer Lambert's law does not predict this kind of a behavior making pattern happening nor the behavior that we saw here like it has some kind of a saturation reached here that happening that is not predicted by this law. So, that is how like you know you start looking at now new kind of a phenomena what is happening here and what is leading to really you know formation of such a patterns which are having like know very strong making behavior observed here ok. So, that is all is explored or investigated further to get to some kind of a you know interesting findings which are published in the literature ok. So, these are the details of the plots how this beer Lambert's law how our results match with the literature beer Lambert's law results and they are falling in the same straight line, but we have carried out some results beyond some like you know exposure levels. So, higher energy exposure when you do there is some different very completely different picture that is observed here and that is what we characterize further and model further and you see that there is a if you model this by our model and compare with the experimental data it gives like very similar kind of a results and this is very interesting finding and these are useful for the cases of if you want to have the needle to have this kind of a making at the bottom that needle will be better gripping the surface of the skin that it is applied on ok. So, those are the kind of application areas one can think about. So, these are like you know we study this implication for the practical purposes for micromenial patch that I was talking about for drug delivery ok and then some micro lenses systems and things like that ok. So, there are different different microstructures fabricated by this process and you can see that you know at very small scale we are able to do interesting structures possibility. So, there are this lens array kind of a structures here ok and here we do not have this undulations on the CAD model, but because of very high intensity kind of exposure you get this very rough surfaces on the on this and they may be useful for some sensing applications and things like that ok. So, these are like you know again we conclude this part saying that we have this different technology and different kind of a little bit different mechatronics for such a technology where we still have a compliant mechanism based scanning systems, but now control and positioning of this for different components fabrication is different ok and again this can be converted into a product for specifically targeted to micro needle patch fabrication by using some kind of embedded programming of micro controllers and having some kind of a human interface you know human machine interface HMI given by some kind of a touch screen or some buttons or things like that ok and then this can be another product which is which through which we can produce different kinds of micro needle patches for many different applications to come ok. So, we will stop here for this application and we will study study let us see any other cases in the similar way. So, one can I mean what one I can see say that you know you can look at this case studies from the perspective of that ok look if I want to get my new kind of a system developed in a similar fashion ok it is not very difficult to do that ok. It is it is just a matter of like you know you looking into things in a different way and see ok I go through this training that that has been received in this course in terms of having different sensors identified for this particular process that I am thinking about what are the different actuators I should identify and then how would I put together these things to make them work and wherever you feel that this particular area is of not your expertise you can always borrow expertise from other places and start putting things together and realize your dream applications in this in this way ok. Thank you very much close this session for now.