Are you still Living in the 3D printing era or have you heard of next generation printing of smart materials where the final Shape …
[Music] hi everybody Welcome to Everyday metalogy this episode is something I doubt you have ever heard of before uh normally we talk about 3D printing but today we taking it one step further we’re going into 4D printing if you know what it is well you’re one of the uh the first movers if you don’t know what it is I think you should uh stay here for the next about 24 minutes then for sure you will learn what uh 40 printing is because this is Advanced uh material technology enjoy the show hi merad hi Peter welcome to the podcast everyday metalogy thank you thank you for having me today we’re going to talk about uh some very special materials uh shape memory metals or shape memory materials because it’s not only metals it in in fact also polymers that can be shaped memory uh formed uh can you give a little background about yourself where you are uh and and what you work on yeah sure um I’m mer mer I am assistant professor at University of TWA the east of the Netherlands uh I’m a part of Department working on design production and management and a specific research group that we have in we are working on Advanced manufacturing so mainly what we do as the name States is on Advanced Manufacturing but most of the projects nowadays we are doing with the main focus on additive manufacturing processes yeah uh Melle I I read your book yeah and uh it was so inspiring so uh do if you have it nearby can you show it because I would love uh to share it with uh with people uh I learned so much about this that I needed to to talk to you yeah yeah um but uh first uh C can you give an introduction to what is a shape memory material yeah definitely um there are different type of smart materials already in the literature and also different research group working on that and one group nowadays at least in last two decades is quite famous and common are shape memory materials so we know shape memory materials mainly with shape memory Alloys or shape memory polymers but they are also the other type of shape memory materials that for example we know the type of shape memory gels or shape memory Ceramics in general shape memory materials are group of the material that have capability to return or revert to their original shape after a kind of deformation yeah and and this shape recovery that we call it can happen based on mainly a specific external stimula could be like temperature could be for example magnet field could be even chemical reaction like pach or mure light and and different things so this group of materials as I mentioned that we call it as a smart material can have a different application and also the different way we manufacture them produce a different product so what we are trying to do to try to understand the material well in the first step and second to understand how to make a new product based on that and use it for the different applications yeah uh so if if we dig into the history of it I I really like uh the the way I heard it was found was by an accident can can you disclose how how it was discovered yeah definitely um maybe the most famous story is about the shape memory Alloys um it was a Swedish um let’s say scientist arander in 1932 he discovered in his lab a specific behavior of the material and then he called it shape memory behavior and it was for a gold cadmium Alloys or composite and 193 uh 1932 seems was very early to discover such a material because 30 years later another scientist or researcher in novel laboratory in us his name was William bowler he discovered nichel titanium as a shape memory material and this is one of the most famous of the shape memory material so far and and lots of obligations in the different industry and then from that time 1962 and on board the application of this material become more common but we know most of the products after 200 in in 20 and nichel titanium Maybe a little bit more information about that we know it as also Niti and also n the other name yeah lots of application about that is for medical specifically and Aerospace applications and nowadays we discuss about how to manufacture them and this is the field I’m working on that yeah yeah I think the NIT no name was Nel tum and and the null was uh the the letters for the place it was uh discovered um this is new to me but the n as I know is n titanium so if if no is something additional I hear from you yeah I’m just disturbing because I have died a little deeper into the uh Nel material it was invented or found in uh 1959 at a Naval Research Center in in us uh in fact the material was uh meant for the cone of a missile because it was developed or the purpose was to develop a material that could take the heat from the re-entry in the atmosphere from the missile uh but more or less by accident uh the myologist working on it found that uh this material had different faces depending on what temperature was but first uh 2 years later in’ 61 uh they found what it uh what it really was so the the ability to work as a Memory Metal uh was not found day one but it took in fact two years to to find out that so back to the show and and I think think it was meant to be discovered as a high temperature material so they they made trials on high temperature applications it it failed but suddenly this new uh uh thing appear that it uh it it could return to its original shape after bending it true that is correct and we have a different type of research about the shape memory Alloys and even about nitinol or ni family so some group of the researchers working on developing a new type of Alloys with different functionality for example if you add additional elements to that increase their temperature or or decrease it so this is one thing people work on that and some people try to understand how to manufacture them instead of conventional manufacturing with additive manufact facturing the field I’m working in MH there are also some people try to use the material as it is for the design of the smart product or features and and this is also some another group of the people so sometimes all these three Fields let’s say work together for a specific purpose to for example as a project to make a specific smart product in the end of the day and that is the interesting field indeed yeah uh but now let’s dig a bit deeper into the technical issues because when when reading about it it’s so difficult to understand why it works so can can you describe what is happening inside the material this uh mtic formation then but it’s going up and down history races uh can can you help me understand better what is happening inside the material sure for for shape memory Alloys when we are talking about shape changing or shape recovery we are talking about a specific temperature that temperature is transformation temperature so mainly what happening is let’s say the changing the material phase from cooler temperature that we call it maride to higher temperature that we we we call it asite so changing the temperature of the phase of the material change the micro structure of the material and based on that that we have let’s call it that magic behavior of the shape memory materials I I can share a picture with you and and maybe that would help you understand it better yeah that could be nice yeah sure it’s it’s very abstract just to to imagine what is happening yeah so what you see here actually this is a typical stress strain diagram that we usually have in all materials but here that you see another AIS that one is temperature so I I want to go through the whole diagram and give this explanation because when we are talking about the shape memory Alloys we mainly talking about two different type of shape memory Alloys a part of them we call them super elastic material the other part we call them shape memory effect so again I back to the explanation I have and that’s one is related to the transformation temperature so the first one that you see here and I have a red dot on the picture yeah is the stress strain diagram and I want to show you a b and c so what we do simply we apply a load on the material and when we apply a load on the material what happened exactly yeah this is a super elasticity let me just this and I need to use also my marker to make it easier to understand yeah so what happened here exactly is when I apply load on the material and when I remove the load the material can come back to the original shape so why and this is because the material is already activated and the material in the aoid phase and what is happening in the super elasticity is exactly the moment that we apply a force in the state the material is activated and is above the transformation temperature however if I choose another type of material or I apply the loads in the temp temperature below the transformation temperature the second situation would happen and the second situation is shape memory effect yeah when I apply the shape they apply the load on the material like C D and E like you see and apply a force on that however I still have let’s say the deformation and the strain here in this area to be able to bring the material back or return it to the orig original shape and then I need to apply a heat on the material and for applying the heat on the material I heat it up the specific temperature and it is normally above the transformation temperature and then after that the material can get the original shape and come back to zero point if I want to give you a good understanding of that just follow the red point I’m already showing you here in this yeah two good example of these two super elastic and shape memory effect material the first one is a super elastic material so what you see in the hand of this person is super elastic NTI wire as I mentioned is already activated as soon as you remove the load from that come back to original shape so it is exactly this area Orange area I already mentioned and the second type of the material you apply low down there like this spring was deformed completely so I’m talking about the green area here and then you increase the temperature like here is heating on top of this stove and then material can recover this original shape so there are mainly two type of shape memory allo that we are using nowadays yeah yeah yeah it’s uh it’s pretty amazing uh when when you talk super elasticity what uh strain level are we at uh because most most material have certain level of elasticity but how much uh do you need before you can call it super elastic the level of strain that we are talking about is 7 to 9% of that however these seven or % could be also related to a different things how you manufacture the materials what is the composition of your materials and let’s say what is the state of the material and the shape and geometry of your material so sometimes in the design process we can play or tune with this strain rate for example imagine if you instead of using a bulk material like for example this pen in my hand use like a ltis structure in a specific shape and you can deform it more so somehow we can tune this strain and and and functional behavior of the material yeah yeah so it’s it’s not only the material is also design of the component on macro scale that is correct for example if I want to give you a real example following I show you earlier um it’s not you to use Niti or shape memory Alloys for a stand for example cardiovascular stands so it’s been long time there are shape memory let’s say a stand in the shape of like a tube shape and uh you know the way they make it uh is combination of conventional manufacturing and newer method so let’s say the con through the conventional manufacturing they make the tube shape of of Niti let’s say ni tube and in The Next Step H they use like laser cutting to make a specific shape of that like a spring shape and and based on cut out material that’s true and and based on that they can make it very flexible and move it to any Direction they want so the structure architect of the structure can help you to make uh or achieve a specific the formation you’re looking so the the typical manufacturing method is it uh melting casting and and then you can roll it and uh and make plates and sheets or are there other methods for manufacturing yeah you’re right um let’s say the main manufacturing process is still conventional so lots of product already available in the markets like in the shape of wires or tubes or let’s say uh stream or plates yeah but what the recent research not even recent let’s say in the last decades or 15 years people from the different groups and from different universities and also not universities research institutes try to subtitute that with the other type of manufacturing process for ex example when I’m talking about additive manufacturing and the whole philosophy of writing the book I show you earlier is exactly about that because what the researcher trying to do uh trying to find a new way to make a complex structures because thanks to additive manufacturing we can have it and we can make complex structure from different materials let’s call it from polymers to metals or Ceramics hydrog so the idea was how we can use additive manufacturing uh processes specifically for shape memory materials that doesn’t matter shape memory polymer or shape memory Al there are different type of manufacturing and 3D printing you can use it and and that’s why the initial idea of this book was okay if we can add or gather all this information from a different researcher all around the world and and and have it documented in in just one unique book and and then we did it so this book of course there are two editor myself and also my colleague Professor Alim but but each of these chapter is written with very famous uh let’s say researchers or research group they work specifically that topic so we have a researcher working on material development and discuss that in the book to let’s say different type of manufacturing process because when we are talking about additive Manufacturing is like powder based wire based DD lpbf and there are many many yeah yeah and and uh we have to remember my my heart is in power metal so oh okay so that’s also important to to mention that they can be shaped with po metall Roots uh yeah that is correct actually one of the uh main let’s say additive Manufacturing process is lpbf or totally PBF process and this is a PBF stand for powder bit Fusion yeah so we still have powder there and we need the powder and there are lots of businesses uh working on how to make high quality powder for different type of shape memory materials but the Ste NTI is a dominant material in the market and in most of application of the shape memory yeah uh meria there was one thing in the book that uh amazed me most it was a new term I’ve never heard it before uh it’s called 4D printing yeah I people have been talking about 3D printing for decade now so when I read this 40 printing it was what is that that is not possible so can you explain what it is what what is going on in 4D printing yes definitely U let’s say Ford printing if I put it in in in very simple way is let’s say integration of smart materials and additive manufact with additive Manufacturing Technologies so the the 3D printing technology exists already if we print a smart material with that then we can have a different let’s say uh shape of the material after the 3D printing because this smart material in response to external stimuli they can change their shape so these 4D or fourth dimension exactly because of that because du to or the response to the external stimuli they can’t change their shape or proper is over the time and that’s why instead of 3D printing of for example shape memory materials they call it 4D printing but I should be honest and say there are also some researcher they do not like to use 4D printing for that and they said there are still 3D printing with a smart material they do not have any problem so we can use both of them 3D printing of a smart materials or 4D print both of them are fine yeah uh and you have some examples on how you can change uh the properties or or add this uh the time scale to to a component and the function of it yeah definitely I have one simple example of for that and this example is for this time for shape memory polymers because of my research I work on both of shape memory Alloys and shape memory polymers although they have two different words and sometimes the researchers working on one they do not necessarily work on the other because we know the materials are totally different but for me is really interesting to learn from both of them and every day in the different research I learn from that so what I’m sharing with you right now is a let’s say a logo printed a print logo of the University of TW the university I’m working for so this is um let’s say a shape memory polymers if I want to be very a specific a combination of PLA and PPS biopolymer like what you see in the first picture is completely rigid material and printed like a normal other 3D printed Parts yeah so the point is you can deform these structures I can give you more explanation how you can deform because like shape memory Alloys that we have transformation temperature shape memory polymer that we have a specific temperature that we call it TG or glass temperature and above that that temperature material can be activated so the point is if you heat up the material above that temperature for example here in this case the TG something about 60° and we could heat up the material like 65 or something deform the material and if you cool it down and then the material get the new shape so the new shape that we see here is a deform shap yeah however if you heat up the material again above that temperature the material can return to the original shape so the video I show you here is the shape recovery of the deform logo and here what you see is happening in a hot water hot water means above that temperature and then the logo can come back to original shape so this is uh let’s say a very typical and common example of Ford printed part how we can recover the original shape and also same thing can happen also for shape memory allo specifically super elastic material so there are some examples and also publish in in the previous work that you can deform the material hit it up it come back to original shape H yeah that was the story about uh the the theory behind this 40 Printing and the shap memory materials in the next episode we’ll take a deeper dive into what is the real purpose of everyday metalog it is to talk about every day applications so come back uh in next episode we’ll uh go into real life [Music] [Music]
