• John Ennis

Yizhou Ma - Printing the Future


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Yizhou Ma is a PhD candidate at Wageningen University in the Netherlands. His PhD research focuses on the adaptive control of 3D food printing. In the past, Yizhou worked as a R&D scientist at Gastrograph AI and obtained his bachelor's and master's degrees in food science. His professional pursuits center around data-driven research and sustainable system design for food productions. He is also co-host of the podcast "Food in the Hood," where Yizhou and his friend Amanda Sia discuss the science of food, its current practice, education, and future development.


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3D Printed Pasta


Transcript (Semi-automated, forgive typos!)


John: Yizhou, welcome to the show.


Yizhou: John, thanks for having me.


John: It's my pleasure. So Yizhou, I definitely want to get into augmented reality in the future, like in about maybe ten minutes. But let's start for the people who don't have enough chance to meet you and maybe haven't had the opportunity to listen to your podcast, to just hear your back story. How did you get to be where you are and what are the things that you are kind of most interested in?


Yizhou: Oh, yeah. Yes, as you've introduced, I'm currently working on my PhD at Wageningen University. In the past, I'm a food science-educated professional and then really were interested in data and interested in, let's say, new tech in the food domain. So in the past, I've worked for a small startup company using it using AI and I've always been someone who was kind of at the interface between the innovation, the newer innovation with the traditional or more mass production of food. So currently I'm a first year. I'm still a first-year doing a PhD in food printing. So 3D printing of foods and particular work on the control of food printing so that it gets consistent printing and move us towards the Internet of Things generation of food printers.


John: Definitely. And so you come from a food science background, so where did you do your undergraduate and then your master's degree? Was that in the USA?


Yizhou: Yes. So currently I'm in the Netherlands but my bachelor was from University of Minnesota and the master's degree I got from Kansas State University.


John: Okay And were you in one of the chamber's lab or who did you do your?


Yizhou: No, I was in the food engineering group. Yeah. So that's how I got more expose with data analysis and move on to that track thereafter.


John: Fascinating. Okay, well then let's get to the main reason should be on the show, which is that I think that obviously there's been tremendous advances in augmented reality when it comes to sight and sound, right? And you look at the various computing revolutions that have happened. You know, really what we've had advances in communications technology. And you think about social media or you think about things like this like where, I mean, it's amazing. Right now we're on Zoom. You're in Holland. I'm looking at you on Zoom, we're recording and it's just like a normal conversation. I mean, it's just completely amazing, right? So there have been amazing advances in sight and sound communication. But I think that the next frontier, the thing that we really have to work out is the incorporation of the chemical senses into this augmented experience that I mean, it's we really we live in an augmented reality already. We take it for granted in a lot of ways we are, you know, interested in so many ways like you drive your car, you get a map, you have a little picture of your car and you're going along and the extra information is coming in. And so I think it would be really important for our listeners to get a sense of what is the current state of 3D printed food that is actually going to eventually be a type of augmented reality where we might have a meal together, where it would be like we're, eventually it may be the case that you go to a restaurant website and you log in and there you are and you're having a meal with your friend and everything is 3D printed at your house somehow. Right? As it can be like here we go and the recipes are encrypted and you have to go to the restaurant to get that recipe or whatever. But it's made on-demand, on-premise, and which of course, has some sustainability benefits as well. So can we just bring us up to speed on 3D printed food, please?


Yizhou: Yeah, absolutely. So what you described there was probably one of the end goals of food printing. So I'd actually want to maybe take us a step back and talk about just 3D printing in general.


John: Okay.


Yizhou: So right now we have a very big open-source hardware community that are basically just people, hobbyists who like to 3D print plastics, various plastics. It's been a democratized technology that you can build yourself a 3D printer for, let's say, a couple of hundred dollars, and that can sustain you for quite a long time. It's a robust machine, hard work, and it's getting better and better. And there are people sharing these free designs that this CAD designs computer designs online and where you can print, let's say, your own figures, your own tools. Sometimes say, for example, if there are some unique tools or unique compartments, that it's hard to get from where you are, download it and print it. It's still, as I said, as the hobbyist level, no official release from companies to do such things. But as you can imagine, it's not difficult probably for, let's say, some designers instead of making mass production of plastic designs. They would just issue and sell these digital designs online and you can print in that whole kind of almost as, well think of this, just like Netflix for designs like plastics anything, or containers that you use at home. So in terms of food, certainly that will be the hope for the future. Do similar things, as you described it. Let's say we have these recipes online that you can download and you are on your way home and you can select what you want to eat. The printer will start work and by the time you get home, something might be already ready on a dinner plate.


John: Yeah. I mean, it almost sounds like science fiction, but what's strange is it's hard to imagine, we just think for 50 years we're videos in the future. It seems inevitable that something like this is going to eventually get worked out. So maybe you can talk about the kind of key problems in the area. So let's hear about that and then the key applications, the places where the technology is being used. But let's start with the key, what are the main problems that people are working on right now?


Yizhou: Right. So what I just described is it's still very far ahead in the future. The current status is more towards that we have specific applications for food printing and that centers around. The most common way of printing is what we call extrusion-based printing. So I joke about this if you have put toothpaste on the toothbrush, you know what a solution is. It's basically squeezing a paste through a nozzle and in the case of 3D food printing, the nozzle is very small. So paste-like materials can be squeezed through this nozzle by a pressure force and it's hooked to a three-dimensional robotic arm that can move in the space. And the material is built layer by layer, much similar to how you would print plastics. And so the catch here then is it's extrusion-based. So you have to print something that's pasty and for that, it already limits a lot from jollier in sensory so that's a pretty big limitation already. Although you can do somewhat we call post-processing. For example, can print cookie dough into shapes and bake the cookie afterward, or you can build some like, say infrared heaters or other types of heating mechanism directly with printers or your printing cooking at the same time. But that's still the limitation, is the shaping process needs to happen at the paste format, let's say. And that really creates a lot of limitations currently in terms of extrusion-based printing. But we do have other mechanisms for printing, for example, powder bags. So is more similar to printing metal compared to the rest of the industry. But that really has also it's very much their limitations that is not really using a lot of water per se. Right? You could print powders and how do you turn that powder into an edible format food while maintaining its shape. That's something it's still quite a long way to go. But that comes in my research as it's to, because even just for these surmisal foods, there are so many different ideologies and textures around it. So that really crays even a challenge for traditional plastic printers because you only have a handful of materials in plastics to print, whereas in food you have a range of materials. You can print mayonnaise, you print cookie dough, protein bars. And all of these require a different set of settings. And that's where my research comes in to help the printer to learn the food by itself and to print as best as it can as intended to based on the computer designs.


John: I see. Now, does the printer have a single, say, tube loaded in it, or do you have a kind of range of tubes? And then it goes through and it picks? I mean, suppose you have the most advanced 3D printer for food in the world? What would it look like? How many tubes would it have? How would it be configured?


Yizhou: So that's a great way to put it. You can have multiple tubes, right? That's another challenge. In fact, it's low in diversity or it's relatively homogenized of a food that currently is being printed. I've seen printers equipped with, you know, three or four tubes where just three or four different materials can be extruded at once to build a single food item.


John: Right.

Yizhou: But for sure, there are many code development or synergies with bioprinting, or let's say medical or biomedical engineers are working on printing human tissues or skins. We are borrowing or sharing a lot of these technologies together and for them, there are different sets of challenges there. But say, for example, instead of a nozzle that can just move X, Y, and Z, you may also have circular axes or other axes to control this angle and to have better movement controls with that to have high fidelity printings.


John: That's fascinating. Okay, so there's a bunch of questions I have about this. For one thing, I mean, to really realize the kind of Star Trek type dream where you tell the computer what to make and it makes it for you, you would need, there's really a dimensionality reduction problem to be solved, right? Because you have many, many variables and you are going to have to get a finite number of tubes if you're going to use tubes to be able to, you know, maybe with small amounts of each tube that combine it together, recreate some experience. So there's that problem, right? And then there is the fact that even if you were to solve that problem, you would still be very limited in the types of food you could make because there would, of course, be you know, you're making things from tubes. So what are some of the more advanced applications that you've seen? Some things that would be surprising to people successes in the 3D printed food area right now?


Yizhou: Yeah, I'd say one of the consumer breakthroughs, consumer product breakthrough was printing pasta. And so let's think of regular pasta or spaghetti that you eat. Just you cook the noodles and you make the sauce and sauce is always on top of the noodle somehow and you mix it up. So other way of thinking of pasta would be that you can print a vessel, let's say a flask or even more artistic flask that can contain the sauce inside. And instead of eating this, the material, the sauce on top of it, you're actually eating and containing it inside of it. And you can print these vessels at very small shapes and you can use to boil them as if you're boiling noodles, but then you can fill it each by itself and then eat it. I think it changes the sensory experience. It's a lot because of the shape and how it's presented. And I think we can insert a video in the show notes, there's a nice video about it to demonstrate the process. It's very foreseeable and is achievable just by an average person if you tell them a little bit about 3D printing. But the result of it is quite powerful.


John: Now, that's interesting because I have been thinking it just goes to show the benefit of doing a podcast. Right? Because you just expanded my mind that, like, I was just thinking, okay, the goal of 3D printed food is to recreate the experience we already have. But now you're talking about new experiences, things that would not have been possible without the technology, which in some sense I think is it's a different type of exciting. Right? Yes, it would be great to just be able to three different whatever you want, but when you now suddenly get access to new experiences that couldn't exist without the technology, that's quite exciting. So, well, maybe we were talking a little bit before the show, too, about where 3D printed food is being used. Can you tell our listeners a little bit about the kind of current applications?


Yizhou: Certainly, yeah, so currently we have, it's still in specialized fields for example, NASA is looking heavily into the 3D printing technology, potentially for spacesuits, as you know, spacesuits are already in paste. So one way shape it in a better place so that astronauts are a little bit happier while working in the space stations. So that's one of the applications and also similar to military foods that are that you can potentially personalize nutrition. So, for example, based on the nutritional needs of the soldiers or the astronauts and to customize food based on that. And then there are applications or research for designing food for people with swallowing issues. So that can be a quite niche medical food application, especially when you combine that with the personalized nutrition component, expanding a lot with the application of 3D food printing. And it's still in the very early development phase for everyday consumer-facing products. Pasta is one of probably the closest one for you to get. And I forgot to mention another big area is in chocolate printing. So that's purely for the shape of it. And but that's already fascinating enough where chocolate as a material can be created into many shapes. And there are commercial companies that sell 3D chocolate printers and you can also get these banquet services from given areas where, for example, if your company is doing a banquet, you can have your logo 3D printed in chocolates and served to your guest.


John: Yeah, well, I hadn't really thought about that, what's new, what's possible that wasn't possible before. That's definitely worth giving a try. That reminds me so as far as your podcast goes, it's very interesting to me that you're also a podcast host. So what was your motivation? And then what have you kind of learned over the course of doing your call?


Yizhou: Yeah, so I've been podcasting for close to two years now. It's a great experience and I really like to have conversations with my co-host, Amanda. We were college buddies, and it's getting harder and harder to find time together to talk. Then we had a few good conversations and we just decided to record them. And that was still when I was working on my Masters, and that was sometimes we were both in grad school and in different universities. So that was a very nice time to kind of just catching up/updating each other. And since then, it has been originated a lot to its current format where we just find common interest in topics and go through them. I personally find it better than blogs because you don't have to get it perfect or near-perfect to be shown to the world and what's recorded light edits and just goes out.


John: Yeah, I find it to be really great. I mean, it's been fascinating talking to so many different people. So let's talk a little about what are you most excited about now? So you're just getting into your PhD research. I'm sure you have ideas about what you want to study, but what are some of the things that over the next few years you're most interested in looking at and then related to that, what would you recommend that other people look at in this area? Maybe you don't have time to do everything. What would be some of the topics that you think are important?


Yizhou: Yeah, as you said, yeah, just getting started. I'm doing work related to control, which I think we've got a lot of excellent food scientists who understand the food materials a lot so we can formulate and control our recipes to make good food that's suitable for printing. But still, it's a consumer-driven innovation and it's always going to be that way. So the printer itself needs to be adaptive to the various formulations that scientists come up with or the developers come up with. So that's where my work comes in, is to get the printers as adaptive as possible to an array of different materials. So that a printer itself becomes smarter and it has the capabilities of printing challenging materials. If you heat it up, you can actually print a lot of proteins and you can probably print protein bars quite easily. But depends on what type of protein bars or do have you know, it goes a gazillion problems with other what I would like syrups and others that you put in there. Right? Really the bottom line is, I think in order for more breakthroughs, there need to be more innovations in the tool designing component and to the development component. That's what I'm trying to do here. Yeah.


John: Now, is it the case that the 3D printer for food is basically the same machine as a 3D printer for plastics and that you just end up with different tubes? Or are there is there an extra degree of customization that's required?


Yizhou: Yeah, so the printer had so what's moving in three dimensions. It's the same. Like nothing would change that you're still drawing in the three space. So what needs to be changed is really the mechanism. It's a little bit different as some of us might have seen a 3D printer for plastics. That you have these filaments which are just long strings of plastics that feed into an extruder. But in our case, the more commonly seen applications right now are just tubes. Right. So you change tubes. So it's essentially a batch process, whereas there are also feeders which are screw extruders. So much like how you make Cheetos but way smaller and you don't expect a puff because it's all under its all lower temperature. So these things are really the difference is there's no prepared rows of filaments to use. The material itself needs to be contained differently before it goes into before extrudes out and built the 3D structure.


John: Right. And to what extent is the field currently interacting with sensory. I mean, we were talking before the show a little bit about how, you know, at one point I was an ambassador between ASTM Sensory Evaluation Group and ASTM Cannabis Group, and when I went to visit the camp, actually I went to a meeting for the cannabis document at ASTM. And it seemed to me like they were still pretty far away from doing sensory and consumer science. At least this was two or three years ago. They were really interested in chemistry problems. In your world, how many of the problems that you're looking at are sensory? To what extent do you interact with sensory science or are you still on the kind of food engineering side without really much regard for the sensory experience?


Yizhou: Yeah, that's a good question, John. We have some sensory studies going on as the initial not only to sensory but let's say consumer research in general. What do people think of 3D printed food? Not a question to ask. And in terms of sensory development, we're not quite at the flavor level yet or taste and flavor level more. There are gradual interest in to texture, especially when you print food. You can formulate parse structures, hollow structures that are difficult to achieve by traditional molding techniques. So that can create again, it's something new so you're talking about to replicate what has existed versus creating some new experiences. And I think people are still more interested or to explore these new experiences.


John: Right


Yizhou: And that comes with, let's say, the different types of power structures for creating different textures because chocolates are easy to print. You can maybe play with the pattern of chocolate to create these illusions of it's just a thin spread in chocolate that is perceived as a large amount and therefore may impact sweetness, perception, etc. So those are the sensory studies that I've seen in this field. Of course, there are more to go in this area, especially when we are more matured with the technology as a real production tool.


John: Right. Have you experience, would you say, did you experience a sensory experience with the 3D printed food that was really novel? But, you know, there are some chocolate bars that are made in various ways that provide unusual experiences. I mean, have you experienced something that you would say is kind of qualitatively different from the 3D printed food?


Yizhou: Yeah, definitely I participated in a few sensory studies for or some of them are informal tastings for 3D printed food. There is a texture change that I can tell compared to, let's say if it's a protein bar or chocolate bar, you can tell the difference and that's quite consistent, that throughout the few sessions I've been to. In terms of the new experiences, I can't quite promise too much in terms of that and I feel I can perceive the difference and there's certainly a liking associate with it, but I think I have somewhere sometime in a different format I've perceived a similar type of texture even if this one is the particular one that I tasted was 3D printed.


John: Yeah, well, I want to try this pasta. If there's any way I can get my hands on the 3D printing..


Yizhou: Maybe. I think there might be a holiday thing, but I forget the brand that would make these pastas. I can look it up and probably share it with the listener later.


John: Yeah. So that's interesting. Okay, well, Yizhou we have managed to go through the time very quickly. This is a real pleasure to talk to you. Do you have any last bits of advice to the listeners, people who are interested in this area? What would you recommend that they which avenue should explore through in this area?


Yizhou: Yeah, so I'm part of an initiative called Digital Food Processing Initiative. My project is a funnel through them. I can share some websites there about all the different kinds of projects that we're working on, about 3D food printing and you can connect with me on LinkedIn. I sometimes share articles and sometimes write about these types of topics. So, yeah, these are ways to kind of keep up with this topic.


John: Yeah. Fascinating. I bet the next 5 to 10 years will show a lot of progress in this area and I think we'll be surprised. It's always true that technology is like going slow until it's going very fast.


Yizhou: Yes.


John: It's going to be an area that as we drove as well. Okay, Yizhou, thank you so much for being on the show.


Yizhou: Yeah, thanks, John.


John: Okay, that's it. Hope you enjoyed this conversation. If you did, please help us grow our audience by telling your friend about AigoraCast and leaving us a positive review on iTunes. Thanks.



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