Published: Sept. 2, 2021

In this episode, we’ll meetÌýDr. John Crimaldi, a professor in the Department of Civil, Environmental and Architectural Engineering. We’ll learn about his early fascination with sailing and how it set the course for his lifelong interest in fluid mechanics. As the Network Lead for the ambitiousÌýÌýproject, he also tells us about this international network working to understand how brains organize and process information from odors to guide behaviors.

Terri Fiez

Hello, I'm your host Terri Fiez, Vice Chancellor for Research & Innovation at the University of Colorado Boulder. Welcome to Buff Innovator insights. This podcast features some of the most innovative ideas in the world and introduces you to the people behind the innovations, from how they got started, to how they are changing the future for all of us.

Today we'll meet Dr. John Crimaldi, a professor in the Department of Civil, Environmental and Architectural Engineering. He is also the network lead for Odor2Action, an international network of scientists, engineers, educators, students, and others, working to understand how brains organize and process information from odors to guide behaviors. Dr. Crimaldi's research interests are centered around fluid mechanics, a discipline which seeks to understand the complex motion of liquids and gases. He is also especially interested in experimental techniques. Dr. Crimaldi earned his bachelor's degree from Princeton University and his master's degree and PhD from Stanford University.

During today's podcast, we'll hear about his early fascination with sailing and how it planted the seeds for his longstanding interest in work and fluid mechanics. He also shares details of his academic journey, including stops at Phillips Exeter Academy, Princeton, Stanford, and finally at ÃÛÌÒ´«Ã½Æƽâ°æÏÂÔØ. And we learn all about his current role as network lead for the NSF Odor2Action international collaboration, which is helping us better understand the most mysterious of our senses, the sense of smell, and pushing the boundaries of science on a variety of fronts. Let's meet Dr. John Crimaldi. Hi John, thanks for joining me here today and I'm really excited to dig in to hear more about your story and your pathway in your career.

Dr. John Crimaldi

Great to be here, Terri.

Terri Fiez

So let's just kind of start. When you were growing up, you had two really big interests, sailing and flying. How did you develop these interests?

Dr. John Crimaldi

Yeah, I was definitely into both of those things. My dad was a pilot. He had been in the Air Force and then was a commercial pilot during my whole time when I was growing up. And my whole family spent time in the summers on a sailboat. To me, in my recollection, it almost feels like we lived on the boat the summers, although it was probably only a couple of weeks at a time. So I was always fascinated with that. I spent a lot of time sailing dinghies, and really kind of obsessing over the way fluid flow moved over the sails and over the keel. And it was really only kind of later that I could look back on that and sort of see that maybe that had some connection to what I ended up doing as an adult.

Terri Fiez

Well let's just kind of go there. So you ended up studying and working in the field of fluid mechanics. So first of all, what is fluid mechanics?

Dr. John Crimaldi

Yeah, I get asked that question a lot. Fluid mechanics in the end is actually pretty simple. It's a branch of physics that concerns itself with the motion of fluids, which in my case are just liquids and gases. It's a bit of an interesting field in that it's still the very active field of study. Turbulence is considered to be still the kind of frontiers of science in terms of things that we still don't understand particularly well. And because of that, it lends itself towards other solution techniques like experiments, which I tend to be very much focused on and also numerical simulations, which I do as well.

Terri Fiez

So in hindsight now realizing what it is you do, do you think it was obvious that this would become the field that you would work in?

Dr. John Crimaldi

Yeah, no, not at all. I don't think I knew as a kid that there were people that hung out in a lab and studied fluid mechanics. The best I thought as a kid, I distinctly remember thinking that I was interested in becoming a Naval architect, and a Naval architect is someone who designs sailboats. And I think my parents convinced me that that was probably a really, really narrow field and I didn't end up going that way.

Terri Fiez

So what advice do you have for students that are thinking about what do they want to do when they grow up? How do they figure that out?

Dr. John Crimaldi

I think the thing I've come to terms with, looking at my own experience but also kind of looking at my kids, is to encourage people to focus on things that really interest them and things that they're passionate about and to maybe not worry at all about how you might turn that into a career. And that's for a whole bunch of reasons. One is that you probably aren't aware of all the different things that your interests might feed into. And boy, especially in this day and age, the world is going to be so different by the time they're actually looking for a career that the careers that they might end up doing may not really even exist now. So I really try, and especially with my kids, when they seem to be interested in something, I try and point that out to them because they may not be articulating that well to themselves.

Terri Fiez

I think that's great advice that you have there. So you had kind of a unique educational experience in high school. Can you describe what that was?

Dr. John Crimaldi

Sure. Yeah. So I was very fortunate to be able to attend the Phillips Exeter Academy, which is located in Exeter New Hampshire. I would think by just about anybody's standards, it's considered to be one of the best high schools in the world. I think much more in hindsight that I really appreciate what it is and how unique it is. But I also think a lot about it these days in terms of privilege. So Exeter was small. There were 250 students in my graduating class. And when I went to Princeton, 22 of my classmates went with me. So it's this kind of pipeline.

And then of course, once I was at Princeton, then that made it easier to go to a really good school for grad school. And coming out of a really good school for grad school, it made it that much easier to get a faculty position. So, obviously I had plenty of other things going for me in my life other than Exeter, but I guess it's convenient to look at that as sort of a single event in my life that really set things in motion. And to be honest, really gave me a step up on being able to follow through on the trajectory that I did.

Terri Fiez

That makes sense. And as you mentioned, you went to Princeton after that. What did you decide to major in at that point, because I doubt you knew what fluid mechanics was at that point?

Dr. John Crimaldi

No, I don't think I did, but I majored in mechanical and aerospace engineering. It was a combined degree. Interestingly though, I did an experimental project that involves sailing. So I brought the sailing thing back into it. I actually did a project where I instrumented a wind surfer with sensors and cameras to study the flow on the underwater appendages to try and understand a problem that was persistent in a lot of wind surfers at high speeds, where the skeg, which is this underwater lifting surface, would ventilate out to the atmosphere and lose lift. And it didn't necessarily work particularly well in the end, you had a limited amount of time to do it, but I've learned a lot from doing it. And I guess that was really my introduction to experimental science.

Terri Fiez

Sounds like a fun experiment to do as a college student. So then after graduation, where did you go?

Dr. John Crimaldi

So aerospace was booming at that point and I ended up getting recruited to Northrop in Southern California. And so I moved right after I graduated college that summer. I moved out to Los Angeles and started working at Northrop. And the project that I was working on was a top secret project. I seem to recall that at that point, I think only maybe two people in Congress knew about it for the funding portion of it. So I was working on the B2 stealth bomber and did a lot of numerical analysis on something called flutter. And I was also in the flight control room for a large number of the first flights of the airplane, which were done out at Edwards Air Force base.

It was interesting. It was an amazing thing to do as someone right out of college to be working on such an incredibly advanced piece of technology. But in the end, you really couldn't get around the fact that that airplane was designed for one thing, it was designed to bring nuclear weapons deep into Soviet airspace. And it was hard to reconcile that with what you were doing on a day-to-day basis. So that's how I ended up pivoting to the career that I have now is that I took the parts of that job that I liked, which was the fluid mechanics and experiments and things like that, but I went back to grad school to learn how to apply that to the environment and to ecosystem dynamics, which is to a large extent what I'm doing now.

Terri Fiez

So you spent about a decade between your master's, your PhD and doing postdoctoral work at Stanford. What were some of the highlights of your time there?

Dr. John Crimaldi

I did a lot of wind surfing. My advisor will be the first to attest to it. Yeah. I was living in San Francisco, which I loved. I worked in an amazing lab with Jeff Koseff and Steve Monismith who in a lot of ways really helped to found this whole interdisciplinary field of environmental fluid mechanics.

Terri Fiez

So then what drew you to Boulder because clearly you had to give up the wind surfing?

Dr. John Crimaldi

I did. I chose very proactively to come to Boulder for a couple of reasons. One was my wife was looking to go back to grad school. And so we were looking at schools that were good for her as well in her field. But for me, and honestly for both of us, I think the decision really came down to Boulder seeming like it would have the best work-life balance for us. And Boulder is just so unique in the sense that you're so close to so many things that you can do outdoors, that you can take a couple of hours off in the morning and be up in the mountains and do something and then be back in the office at nine o'clock and it's like nobody even knew anything happened.

Terri Fiez

So I just wanted to hit on a personal note here. I know after early in your time here in Boulder as a professor, you were diagnosed with MS and you've had to deal with that since that time. How was that first identified and how have you learned to live with that?

Dr. John Crimaldi

Yeah, no, I appreciate you asking about it. It's certainly been a big part of my life here. So about 15 years ago, over a fairly short period of time in about a week, I slowly but surely lost pretty much all feeling in my body from about my upper chest down and fairly quickly was diagnosed with multiple sclerosis, which it's a progressive neurological disease. And yeah, there was a lot of uncertainty then being diagnosed with it. And just as I was starting out in my career, I didn't even have tenure yet. I just looked this up recently. I think to this day, the statistic is that roughly 70% of people who have MS are unable to stay in the workforce after 10 years of their diagnosis and I'm at 15 years now so I guess I'm still beating the curve. And I've managed stay reasonably healthy. I'm on a hundred thousand dollars a year worth of meds, which are not necessarily all that effective in the first place. I think I've probably been doing well mostly by trying to stay very, very active from an athletic perspective and maybe some good DNA.

Terri Fiez

Has it changed your perspective in any way?

Dr. John Crimaldi

Yeah, I think it has. As anybody who's had a diagnosis of something like that or any other number of big life events, it forces you to reevaluate your priorities and kind of remind you maybe earlier than many people start thinking about it, that you are of course mortal and aren't going to live forever. And I think I've been better about trying to carve out time to do things other than just work all the time and certainly have taken much, much better care of myself.

Terri Fiez

Well, thank you for sharing that. I'd like to switch gears a little bit. We'll talk a little bit about your research career, but I also want to talk about your teaching. What classes do you teach at ÃÛÌÒ´«Ã½Æƽâ°æÏÂÔØ and what are your favorites?

Dr. John Crimaldi

So everything I teach involves fluid mechanics. On the undergraduate side, I teach a class called theoretical fluid mechanics, which is a required course in the civil environmental and architectural engineering department that I live in. And at the graduate level, I teach two other fluid mechanics courses and all of those involve Navier-Stokes equations and effective diffusion transport equations. So I teach a fairly narrow repertoire of courses.

Terri Fiez

You had kind of a unique opportunity to be part of what is called the National Science Foundation Ideas Lab. Can you describe what that was?

Dr. John Crimaldi

The Ideas Lab are these funding competitions that NSF does from time to time. And they might cringe if I describe it this way, but I think people who've been through will agree. It's a little bit like reality television. There's usually a large amount of money involved and they invite a small set of people to some relatively secluded location and you go there for a week and you don't know who's going. And in our case, there was $12 million in the other room somewhere. And they were going to give out that $12 million at the end of the week. And you do all these team building exercises and all these different things. But in the end, they tell you to go out and start forming teams and brainstorming and pitch ideas to panels that they have there. And at the end of the week, they can't come right out and say they're going to fund you, but you sort of get that they are. They say, "Okay, go home and write a proposal. It's due in two weeks." And then they basically fund it.

The way I got involved with that, the one that I went to was called cracking the olfactory code. And so it was about olfaction and sense smell, which was not something I knew anything about. And it was a neuroscience project and I'm not a neuroscientist. They wanted to understand how animals make use of odors to navigate towards things or to discriminate between different odor sources and so forth. And I did have a history of studying how turbulence transports different things. I hadn't looked at odors too much, but I had done some previous work on that. And I certainly knew the physics. So it occurred to me, well, hey, why pass this up?

And so I sent them, as an engineer, I sent these neuroscience folks an application for this thing saying that, Hey, if you want to understand how animals use odors, probably be really good to understand how those odors are transported in the environment. And lo and behold, they invited me to come to this thing and I got there and other people were starting to realize the same thing I had said, which is, it probably was important to understand the transport of the odors. I certainly wasn't the only person in the country who knew how to do that, but I was the only person who was invited to this thing who knew how to do that. And so all of a sudden I was in a good position to do that and became part of this team. And this was not the team that I'm leading now, but it involved a lot of the same people. And so I ended up leading that team and we worked on that for five years and that eventually led to the project that I'm working on now.

Terri Fiez

So let's talk about that. You've been awarded a proposal called Odor2Action, which is a really interesting title and concept. And it had a big mix of disciplines. Talk about what that is and who's part of it?

Dr. John Crimaldi

ure. So Odor2Action is a team of interdisciplinary and international scientists. There's 16 all together. I'm the lead. And we are first and foremost, trying to address a very fundamental question in neuroscience, which is how do animals use information from odor stimulus in their environment to guide natural behaviors. So it's first and foremost, a neuroscience project. It's funded through something called the NeuroNEXT funding initiative. And NeuroNEXT aims to advance next generation technologies in neuroscience to understand brain function. And so we are using sense of smell as a vehicle for understanding brain function. And of course, to do this, we use a range of different animal species, including the fruit fly, Drosophila, that have a neural network that has already been sequenced and understood. And so by using simple animal models, we can start with simpler systems and then work up to more complex brains.

Terri Fiez

I can think of all kinds of questions about that, thinking about dogs and cats and their sense of smell and how it's so different from ours and what they can do with that sense of smell.

Dr. John Crimaldi

Well, I'll tell you quickly. I have another project that I'm working on right now with the army where we're helping to figure out how to best train military working dogs to detect explosives that may be hidden in things like vehicles that are entering a military facility or something like that.

Terri Fiez

Very interesting. So tell us a little bit more about this grant. You talked about what some of the goals are. When you're successful and even just thinking out beyond maybe 10, 15, 20 years from now, what will this information lead to?

Dr. John Crimaldi

I think there's a couple avenues for that. The most obvious thing is it's leading to more direct understanding of how the brain works. And I think the aim is that down the road, by making advances into the mechanistic processes by which the brain functions, this can lead to any number of positive outcomes in both science and in public health. So, understanding Alzheimer's and other brain disorders will be much easier to do if we understand the mechanisms that the brain is using to function in the first place. So there's obvious kind of public health things there. There's another, from a more engineering side of things, sense of smell is actually one of the less understood of all the senses. And it's the sense that has been least replicated in autonomous systems and in industrial automation. So for example, we can build robots that can use cameras to see and microphones to listen and sensors to sense touch and so forth.

But when it comes to things involving chemical odors, chemical signatures in odors. So for example, if we are searching for explosives in a car or explosives in your luggage when you go through TSA, or if someone who's buried in an avalanche or for looking for any number of things, the best technology that we have for that today is not some autonomous robot, but animals. So we use animals to search your luggage. We use pigs to search for truffles. We use search and rescue dogs to look for people that are lost in the woods or buried in avalanches. So we hope that some of these technologies that we're developing and some of the knowledge that we're developing will lead to better ability to develop autonomous systems to do search and rescue tasks, or just search tasks in scenarios where it's dangerous or expensive or inconvenient to use animals to do that.

Terri Fiez

So you maybe alluded to this, but I'll ask it more directly. What are you most proud of in your career and what do you want your legacy to be?

Dr. John Crimaldi

Well, I guess I don't think about having a legacy that much, but I am really proud to be leading this team that I am right now, mostly because it's such an exceptional group of people. And just to be part of that and to learn from them and to help keep that team functioning and being effective. I am really proud of that. It's not something I was necessarily trained to do, and it's been fun and exciting to go in that new direction in this later part of my career. But honestly, I think the thing that I get to this day the most satisfaction out of is doing science myself. And I do science on this project as well, in addition to being the lead. And so, I don't know, I think the thing I'm probably the most proud of, or the thing I get the most satisfaction out of is doing really detailed, careful, experimental science in the laboratory and teaching my students.

Terri Fiez

Final question. What are you really optimistic about in the next couple of decades related to your field and how it's changing?

Dr. John Crimaldi

Well, specific to fluid mechanics, fluid mechanics is definitely changing a lot. If you went back into the fifties and sixties, there was people who studied fluid mechanics were studying hydraulics. A very engineering focused version of fluid mechanics. Trying to understand how fluid moves through open channels and pipes and things like that. And that was all very important, but then became very well understood and people moved on to more complex things with airplanes and rockets and so forth. But even those things became things that we had a pretty good set of tools for doing. And so by the time I was in graduate school, interdisciplinary science was becoming big.

And so what people typically meant by interdisciplinary science in those days, and to some extent now, and I did a lot of this and continue to do a lot of this, is that one person from one discipline would team up with another person from another discipline. And so I did a lot of things like that, where I would be a fluid and [inaudible] and I would team up with say an ecologist to study some physical ecological interaction problem. I think the future, and I'm saying this obviously from my perspective as being part of this large international team right now, I think the future of many fields of science and certainly for fluid mechanics is large scale team science, where now it may be a dozen people from a dozen fields that are working together on a very, very large scale project with a tremendous amount of complexity. And the challenges in doing that type of team science are the technical challenges are obvious, but that's only one part of it.

The thing that people are not necessarily trained well to do and that people are still figuring out best practices for doing this, is how do you get those dozen people with dozen different backgrounds and a dozen different ways of approaching problems, how do you get those people to work together effectively so that you can really do something transformative that will change the world? And so that's something that I've been getting more and more interested in. And I think certainly there's a tremendous number of people who are thinking about that these days. And to me, I think that's a big part of the future of science.

Terri Fiez

Well, thank you, John. This has been a really fast and in conversation. I appreciate you taking time to share your thoughts with us.

Dr. John Crimaldi

Thanks so much, Terri. I really enjoyed being here.

Terri Fiez

I hope you enjoy today's conversation with Dr. John Crimaldi, a professor of civil, environmental and architectural engineering and network lead for the Odor2Action project. To learn more about the Odor2Action project, please visit . For more Buff Innovator Insights episodes, you can visit colorado.edu/rio/podcast. I'm your host and Vice Chancellor for Research & Innovation at ÃÛÌÒ´«Ã½Æƽâ°æÏÂÔØ Terri Fiez. Thanks for joining me for this episode of Buff Innovator Insights. We'll see you next time.