The Materials Universe Podcast — Season 2 Episode 4 — The IR Sandbox

[00:00:00] Bailey Tibbett: Hi, everyone, and welcome to the Materials Universe. I’m your host, Bailey Tibbitt, and I’m here with our producer, Audrey Colgrove.

[00:00:07] Audrey Colgrove: Hi everyone.

[00:00:08] Bailey Tibbett: And today’s special guest, Dr. Dan Wasserman.

[00:00:11] Dan Wasserman: Hi everyone.

[00:00:12] Audrey Colgrove: Awesome. Well, Dan Wasserman is a professor of electrical and computer engineering in the Chandra family, , School of Engineering at the University of Texas at Austin.

[00:00:21] Bailey Tibbett: Yep, we’re really excited have you here, by the way, Dr. Wasserman.

[00:00:24] Dan Wasserman: a pleasure to be here. Thank so much for inviting me.

[00:00:27] Audrey Colgrove: Yeah

[00:00:27] Bailey Tibbett: Yeah, so I think maybe just to start as like a brief introduction of kind of like what your lab does in terms of your research and kind of how it applies to material science.

[00:00:37] Dan Wasserman: So my lab is the Mid Infrared Photonics Lab at the University of Texas at Austin, which means that we work with mid infrared light. , and what I usually say is that my group designs, grows, fabricates, characterizes material structures and devices that either emit, detect, or in some way manipulate infrared light.

a lot of that work is using semiconductors. So we engineer semiconductors to have the electronic and optical properties that we want to either generate or detect or, . Modulate or manipulate infrared light. But we’ve also expanded into a range of other materials and structures. But our main goal is to sort of work in the infrared and design optoelectronic devices and optical materials that work with this wavelength of light.

, I would say. Over the last few years. The mid infrared photonics, , moniker has become perhaps, a little bit, , it’s, it, we’ve expanded from just the mid IR, so we, we work now down to near infrared, even visible wavelengths, and, out to, you know, far infrared and, terahertz, so, but I think it would be, , too much of a pain to sort of rebrand the entire group, so we’re sticking photonics for now.

[00:02:04] Audrey Colgrove: Why, um, what makes infrared so special for you guys? Like, why are, why the focus on infrared?

[00:02:10] Dan Wasserman: I think there’s two main reasons and that’s a, that’s a really good question. So, When I started as a professor, as a PI, , the mid infrared was something of a frontier. Uh, there weren’t that many people working in it. I had done a fair amount of work in that wavelength range as a PhD student, as a postdoc.

so, I’d always been sort of interested in it. And there was sort of an opportunity there to do new science and interesting work. But, fundamentally, I think there’s Two real reasons why you might be interested in the mid IR. , the first is practical, just applications. The mid infrared is the wavelength range typically associated with thermal emission.

So the light that we’re actually all emitting right now, I don’t know if you’ve ever seen one of those like, night vision cameras, or like the way the predator sees things, that’s, that’s mid IR. That’s a thermal image. and so detecting, you know, black body radiation from from people, uh, or objects, has real applications and security and defense and energy monitoring and things like that.

it’s also a wavelength range where you have a large number of molecules that absorb light very efficiently and with very distinct sort of spectral patterns. So it’s often referred to as the fingerprint region of the electromagnetic spectrum. So you can identify the presence of a gas by looking at what their spectral fingerprint is in the mid infrared.

There are also sort of astronomy applications. So looking at infrared signals from way out in in the galaxy. And, there’s also atmospheric transmission bands there. So there’s a number of sort of practical applications for sensing and spectroscopy and imaging and even free space communication. So that’s the so depending on who you’re asking for money like that might be the pitch that you make.

, there’s a second reason and that’s sort of As an academic, perhaps the reason that I’m more attracted to, which is fundamentally, a lot of us who sort of work in optics or optoelectronics are interested in light matter interaction. So the way that light interacts with materials. , and, , , it’s not just here’s a material.

Let’s figure out how light interacts with that material. But usually it’s how can we design materials that interact with light in some way or another. And in the mid infrared, one of the really cool things is that you have all of these different light matter interactions that are available to you. So you can use free electrons, so electrons that are sort of sloshing around in the material, you can use those.

You can use, , you know, transitions between bands and semiconductors. you have dielectric materials, you have metals behave like perfect electrical conductors in the mid IR. So you have essentially perfect electrical conductors. You have, , phonons, which are vibrations of crystals, and those have mid infrared resonances on you have nonlinear response, and you can engineer nonlinear response.

So you have this really wide optical toolkit that’s not just available to you, but you can actually engineer these material properties in some cases. So you have this like massive toolkit to design materials to interact with light in the way that you want. So that’s sort of the more.

, at least from a intellectual curiosity point of view, , that’s why I really like working in the mid infrared.

[00:05:43] Audrey Colgrove: It’s like a light sandbox.

[00:05:44] Dan Wasserman: sandbox. Exactly. That’s exactly what it

[00:05:47] Bailey Tibbett: not mid technically.

[00:05:48] Dan Wasserman: technically. Ha ha ha.

[00:05:51] Audrey Colgrove: Awesome

The next part of your research that we were kind of interested in was doped semiconductors, and we were curious if you could explain those to us.

[00:06:00] Dan Wasserman: Yeah, of course. , so I, I mentioned earlier that, you know, one of the things that you can use to interact light with matter are free electrons. Uh, these are electrons that are free to move around a material. So typically, like, if you think about a metal, like gold or silver, you have a lot of free, a ton of free electrons.

So those electrons can move all over the place. And they’re the reason, for instance, that metals are reflecting. There are a number of sort of interesting optical modes, so ways that light can travel along materials or gets, , localized on a material, , that use free electrons. , but in the mid infrared, for a typical metal, there are too many electrons.

There are just too many electrons. So the metal behaves, like I said earlier, like a perfect electrical conductor, which has applications and is interesting, , but is also limiting. So one of the things that we started playing around with, gosh, now, probably 13, 14 years ago, was, well, what happens if we started with a material that had no electrons, and then we started adding them.

So could we approach an optical metal from the too little electron side and add them? Because it’s very hard to sort of take away electrons. So it is actually something we’ve been working on lately. So we started with the semiconductor and we just started doping it. So that’s when you basically add an atom that has an additional, , electron.

And that electron sort of moves into the semiconductor and can slosh around in the semiconductor. So what we’re basically doing is we’re creating designer metals because , if you get like gold, gold has the number of electrons it has. There’s nothing you can do about that. , but if you start with a semiconductor and you can control how many electrons you put into it, you can essentially control how metallic it becomes.

So we’re engineering our own metals. And then because these are semiconductors, that means that you can now grow them. at the same time, you’re growing these sort of complicated electronic structures. So we can integrate our Dope semiconductor metals with detectors or emitters or LEDs or what have modulators and we’ve done all of those things over the past decades, , using these, the sort of doped semiconductor, , architecture.

[00:08:21] Audrey Colgrove: So it’s like steroids for elements

[00:08:23] Dan Wasserman: Ha ha ha ha yeah,

the doping, the doping is not, uh,

uh not

[00:08:28] Audrey Colgrove: steroids. No, it’s making them work better

[00:08:32] Dan Wasserman: right That’s right. That’s right.

[00:08:34] Audrey Colgrove: I love that

[00:08:35] Bailey Tibbett: It makes great acronyms if I do

say so myself

[00:08:37] Audrey Colgrove: I do say so

[00:08:40] Bailey Tibbett: , along that vein, are there any designer metals or designer semiconductors of interest as of late that you find yourself just obsessed with? I

[00:08:52] Dan Wasserman: the materials that we work with, it’s a careful balancing act because , what we’re trying to do is we’re trying to design and grow and fabricate optoelectronic devices that have, , a engineered photonic environment, namely that we’re controlling the way that light interacts with this material.

But we also, at the same time, have to make sure that the material’s electronic properties are suitable for the application, right? So if you’re trying to make a detector, it’s very important that you minimize dark current. You don’t want tons of current going through your detector that’s not associated with signal.

That just turns to heat. it’s noise and it destroys your signal. So my students, not me, but my students have to figure out how to design band structures so that everything lines up and we get minimal dark current, but also that our detectors, for instance, absorb light at the right energies.

And then on top of that, they have to engineer the sort of photonic environment. And so there’s sort of trying to design these devices on multi dimensional parameter space, which is very challenging, and it doesn’t leave a lot of room for falling in love with a given material or a given, uh, structure.

You have to be able to adapt and adjust depending on what the application is. so we typically, for our DOPE semiconductors, for a variety of reasons, , we try to use What are called narrow band gap semiconductors. So these are semiconductors that have a very small energy between our energy gap.

, it just turns out that they tend to become metallic a little bit easier. , And then what my students have to do is what’s called heterostructure engineering, which basically it means stacking a bunch of semiconductors together to get the optical electronic properties that you want.

[00:10:49] Audrey Colgrove: Awesome. Well, speaking of your, your lab group, uh, your, group has doubled in size in the last four years. , how has this growth come about?

[00:10:58] Dan Wasserman: I don’t so, I mean, , any, any group grows or shrinks based on, , what the students are able to achieve, and I’ve been very lucky to have, a fantastic group of students, , who work very hard, and who have gotten some very nice results, and then, the way that it works is that, you know, a student gets a great result and then you can go pitch that to a program manager or write a proposal based on, , , don’t know that it was a sort of calculated effort to grow the group.

, I think it’s one of those things where You’d rather be growing than shrinking, in general. I mean, I had always imagined that my group would be myself and four grad students. That’s sort of the way I pictured being a professor. Um, I also pictured, like, being a professor meant that you got the summers off.

And also, I had all sorts of like

terrible ideas of

what the job was actually like. Uh, I was, uh, yeah, I was delusional. Um, but You know, I think it’s, in some ways it’s hard to maintain a group of only four students. Um, in some ways it’s a little bit easier to have a larger group. , but there are, of course, challenges associated with having a larger group.

Yeah.

[00:12:22] Audrey Colgrove: Can you expand on those growing pains?

[00:12:25] Dan Wasserman: growing pains? Yeah, well, I mean, I think, When you have a larger research group, it means, of course, that you need to raise more money to support the students, right? So, typical student in an experimental research group is probably, , give or take about 100, 000 in research funds.

Once you add up, you know, , stipend and fringes, all the sort of stuff that it takes to support a student, and then, of course, you need to make sure that they have the equipment, that they can do the research, and that they can get into the clean room, and all these sorts of things. , so, as your group gets larger, you have to raise more money, and so you spend less time doing the things that I always sort of thought were associated with being a professor, like thinking about science, more time writing proposals and also, dealing with, program reviews and, and program reports, all that sort of stuff.

So, and, but at the same time, now you have more students. And so, even if you didn’t have all these sort of additional pressures to, in terms of the funding side of things, you still need to Make sure that you’re, you know, giving attention to your students, uh, and it becomes harder and harder to do that.

Uh, so I think that’s the big problem is not only do you want to give the same amount of attention to your students, so that takes more time, but then you have less time because you’re spending more time doing, you know, program reviews and these sorts of things, reports. Yeah.

[00:13:52] Bailey Tibbett: it definitely sounds like uh, a multidimensional problem. Kind of similar to what you were talking about with the heterostructural engineering.

You know.

[00:13:59] Dan Wasserman: It is, in some ways!

Trying to fit everything. And so you have to sort of come up with ways to, , to make sure that no students fall through the cracks. , but also make sure that. students get their stipends and can eat and they can afford rent and all that sort of stuff. So, um, you know, one of the things I started doing was I have, , individual meetings with all my first years for their first year.

So I try to make sure that no first year student falls through the cracks. Um,, and so it’s just a, you know, an hour every week that I set aside to meet with. My first year students. Of course, we, you know, we of course have group meetings like every other research group. , and then, you know, every once in a while we try to get together outside of, , the MRC, , building, do something, , a little bit more fun.

[00:14:46] Bailey Tibbett: Oh yeah, I’ve heard of those OSGMs.

[00:14:50] Dan Wasserman: That’s Professor Bank’s old school group meeting, right? Yeah. Um, yeah. So he does that. My students attend those. Professor Bank and I have a really close working relationship. And so our groups are very much intertwined. So every year I, I have a Thanksgiving dinner that I cook for both of our groups.

And then I try to invite , some of the new professors and their groups to that. So that’s usually like 20, 30 people. So I have to actually make two turkeys for that. Um,

[00:15:18] Audrey Colgrove: Answered my question. That was my next question, how many turkeys

is that?

[00:15:22] Dan Wasserman: Two turkeys, like two big

turkeys, though like

20 pound turkeys. Yeah, so that, but that’s always, nice opportunity for like, , the group to get together outside of lab.

[00:15:31] Audrey Colgrove: We’ve also heard rumors about, um, what was it called? It was the, like, the group getaway.

[00:15:39] Bailey Tibbett: the group retreat.

[00:15:40] Dan Wasserman: Yes, yes,

[00:15:42] Audrey Colgrove: Laughter. Um,

[00:15:43] Dan Wasserman: We have a group retreat. Um, you know, we have a faculty retreat that I hate, uh, it’s super boring and we have to sit through, you know, an entire day of, of this. And I thought, well, if I have to do that, then I, you know, my students should have sit through that too. Uh, so we started a group retreat, , that we’ve now done, I think, basically, honestly, almost every year that we’ve been at UT.

, but it, it’s a, sort of a group retreat but it’s sort of more functions as an onboarding for the new students. So all of the, the returning students give, you know, a 10 to 15 minute presentation about the research. So the new students get a chance to sort of see what’s going on in the group, what the different projects are.

and then I also spend some time talking about, you know, how the group operates, which is important as your group gets bigger, you sort of need everyone to be on the same page. , and that can be stuff as simple as, you know, how do you write a paper, right? Like, what is the theoretically, like, how do you construct a paper, What tools do you use?

How do you make the figures? Like, you know, we use, for instance, we use Overleaf now, right? Which is a, an online latex editor. Which, if a student sent me a paper in Word, at this point, I wouldn’t know what to do with it. and so things like that, you know, how do you think about, how, how do you get to go to a conference?

How does that work, right? How do you put together a conference presentation? All these sorts of things that, guess you might figure out over four years, uh, working in a group. I sort of try to lay out, you know, how we do that. And then, and then part of it is expectations. What does it mean to be a grad student?

How is it different than being an undergrad? It’s extremely different. And a lot of people struggle with that transition. It’s not. No one tells you that being a PhD student, like a lot of people think it’s just, Oh, it’s just another five years of school. It’s not, it’s very, very different. Uh, , so we do take some time to talk about, what is it, what does it mean to be a PhD student?

And we talk about things like imposter syndrome and we talk about, how hard a PhD is and how, what are the tricks that you can use to get through it and, and to enjoy it and, and have it be a positive experience. And, and then also expectations. So what they should expect from me as an advisor and what I expect from them as graduate students.

Yeah.

[00:18:04] Audrey Colgrove: So no campfire songs, is what I’m hearing at group retreat. I

[00:18:08] Dan Wasserman: No, no singing and dancing.

[00:18:10] Bailey Tibbett: like any retreat that’s mandatory probably not gonna be that great , to be

[00:18:14] Audrey Colgrove: funny,

[00:18:14] Dan Wasserman: know it’s it’s funny like we used to do it. So the most of the time we did it in just, we just book a conference room, you know, in MRC and we would have. Eight hours of sitting in a conference room and this year, my students sort of revolted a little bit, which is not to say that I have revolting students.

It’s just that they sort of, um, said, you know, Hey, what if we did it somewhere else? So we rented, um, there’s this like old mill up, uh, sort of in, in, uh, gosh,

[00:18:44] Audrey Colgrove: Green? No.

[00:18:45] Dan Wasserman: I don’t know where it is exactly, but it’s, it’s up north. and so we rented, we rented this mill, this historic mill for the day. And then we sat inside in a conference room and talked about science for eight hours.

So I don’t, I don’t know if, I guess it was better. Um, but, uh, I mean, still there’s a certain amount of material that you have to get through. So my poor students have to sit through that every year. So and you know, a lot of the things that I say are. You know, for the new students. So the, the returning students who’ve now heard this three, four times, , must be bored out of their skulls.

So,

[00:19:20] Audrey Colgrove: Wait.

[00:19:20] Bailey Tibbett: it’s like a love hate experience. I feel like, when I talk to a lot of first years, and then, you know, having been a first year PhD, like, first gen, I had no idea what was going on. So it sounds like, even though it might be, like, eight hours of tutorial, definitely sounds like something that would be, extremely useful for kind of streamlining your group, getting people on the same page.

Right,

[00:19:40] Dan Wasserman: Yeah. And, and getting to know what is going on in the group, right? Like what are the different research programs? What are students doing? , where might I fit in? What’s, what’s interesting. Yeah.

[00:19:48] Audrey Colgrove: Well, and obviously something was working because they were willing to work together to strike. They had developed enough relationships to form a union and move the conference room off campus.

[00:20:00] Dan Wasserman: Yeah, I mean I think that I mean I hope that my students are

comfortable sort of telling me, when things need to change or when there’s a problem or something like that. And actually, that’s, that is something that I’ve worked very, you know, one of the things if there is like a conflict in the group as a professor, you might never hear about it.

Right? Because if there’s a real conflict in the group, they’re not going to announce it in group meeting. Um, so one of the other things I do is that every, at least every year, I take everyone out to either breakfast or lunch individually and just chat about how are things going. And that’s an opportunity for them to talk about, you know, not just how things are going in lab, how things are going, sort of the dynamics in lab.

And then also, you know, talk a little bit about their career path and what, , what they see, , coming forward. Yeah.

[00:20:47] Audrey Colgrove: So you’re a mentor, a boss, and also HR?

[00:20:54] Dan Wasserman: Well, I mean, there’s no doubt that the, PhD student advisor relationship is a unique relationship. you know, it’s part apprenticeship, uh, it’s part sort of employment and it’s part teacher student. and there’s definitely been situations where I’ve had students who only looked at me as a boss and that didn’t go very well actually, because, you know, we don’t pay enough to be good bosses, unfortunately, I mean, that’s just the right.

I mean, the, the, the student stipend is enough to live on. We all like we all, all of us professors lived off that student stipend at one point in our lives, but like it’s enough to live off, but it’s not, it’s not a huge amount of money. So if we’re just a boss, we’re, we’re pretty bad bosses just on, on that, on that, metric at least.

[00:21:47] Bailey Tibbett: Yeah. I mean I think, topics that we’ve explored a little bit on this podcast as a whole kind of been how people’s individual manning managing styles kind of like impact their research how their research almost seems to impact their managing style. So it’s like, you know, you’re talking about versatility and materials and needing to find like different unique disadvantages and advantages.

And it sounds like you also do that with management in the group, which I think is so interesting. It feels like. Like a professor’s research is almost indicative, somewhat, of kind of how they like to run things and how they like to think about the world. So we always love hearing more about that.

[00:22:20] Dan Wasserman: Yeah I think I think one of the things about my group that I’ve tried to maintain is that Every student in my group, in addition to needing a background in optics and, you know, semiconductor devices and semiconductor physics and material science, so they have this sort of breadth to their sort of textbook knowledge.

, I also try to make sure that every student in the group learns how to do design and modeling and simulation. a lot of them learn how to grow materials. they all need to know how to fabricate materials and they all need to know how to characterize materials. So there’s a sort of vertical integration as well.

I don’t, know that that’s the most efficient way to get things done. I think there are definitely a lot of groups where it’s more assembly line, that’s definitely better for me in terms of research output, but I don’t know that it’s better for the students because the students can’t anticipate what type of jobs are going to be looking for.

you know, it’s probably best if they’re very well rounded when they come out of my group.

[00:23:30] Audrey Colgrove: This is something I’ve thought about a lot. You know, someone who’s come out of college in the last six years and got a master’s degree. They’re kind of using your education to pursue the jack of all trades, master of none. It’s better than a master of one kind of thing because the job market is changing so rapidly.

Like you can enter college or your PhD and the jobs that. Are going to exist when you enter, not going to exist at all when you leave, or will have changed completely. Um, so, sounds like you’re building whole humans and not just researchers.

[00:24:02] Dan Wasserman: Well, you know, that’s an excellent point. And I think, you know, we as professors have to always be very, very careful because there is a lot of pressure from, you know, industry. Like, they want students coming out with specific skills.

And this is not undergrads, too. Like, they want students who know how to do X, Y, and Z. And, you know, that’s of course because they’re hiring students. next year or the next couple of years, right? So these are the things they need in the next couple of years, and, you know, in the short run that that’s better for the students, but we have to think carefully about, you know, what sets our students up best for long careers, and long successful careers.

So, you know, one example I always give is I had a student when I was at Illinois, who. his sort of final capstone to his Ph. D. Was he was designing what we call the photonic wire. So basically, when you have an electrical wire, You rarely think about a wave sort of property like electrical wave propagating on that wire, even though it’s typically how signals are.

carried because the wire is usually much smaller than the electrical wavelength. So we tried to do the same thing in light. We tried to make a waveguide where the wavelength of light was, essentially infinite. and so It mimicked the way that electrical wire behaved, so he did it. He eventually did it.

He spent a lot of time trying to figure it out, and he eventually got it to work, and it worked at something like 15 microns, which is a wavelength that is utterly useless for, most applications. You know, it was a proof of principle. Hey, this is a neat thing that you could do. and He ended up going to work for Apple in their sensors department, and he’s actually making sensors like, and I assure you that the sensors he is making have nothing to do with, uh, epsilon near zero photonic wires.

But the whole point of a PhD is to generate students who can tackle big problems that have not. that don’t have answers in the back of textbooks, right? These are supposed to be problems that no one has done before. that don’t have answers that you can look up. And then if you can successfully figure out how to do that, then the idea is that you can tackle.

Any, any problem, whether it’s, you know, designing a sensor for Apple or whether it’s going to work in a national lab on an entirely different technology, right? So our students, I believe, are better served if you give them like a breadth of understanding. And, you know, I think most employers would in the end appreciate a student who can solve difficult problems on their own, as opposed to a student who’s been trained to do a sort of narrow thing.

[00:26:48] Audrey Colgrove: It reminds me of a topic we talked about, um, with Dr. Incorvia in our last episode, about the kind of change in the education world, and its approach to, like, STEM education, because it’s this idea that from a young age, you should start teaching them how to problem solve instead of just teaching them the science.

So I like that it follows, you know, all the way through grad school.

[00:27:12] Dan Wasserman: It does. I mean, look, students need the basics. You need the foundations, right? Like you have to know your multiplication tables, right? You have to be able to take an integral or a derivative, right? There are, of course, core things that you have to sort of drill into students heads, but ultimately, yes, they need to be able to solve problems.

That’s right. Yeah. Difficult problems, ideally.

[00:27:34] Bailey Tibbett: we’ve talked a lot about, like, different aspects of being a professor. Is there any particular aspect that you find yourself, , enjoying the most?

[00:27:42] Dan Wasserman: There are a lot of great things about this job. There A lot of challenging things. But the the great things are, I ultimately, we get to choose the problems that we think are interesting. and if you can convince someone else that it’s interesting, then you get to work on that, which is pretty neat.

the other thing I would say would be, you know, getting to work with students and getting to see students evolve and grow, is extremely rewarding. you know, you have students who come in and they can’t do anything, right? and I, I’m talking about like grad students, but also like undergrads.

I, I teach the, I’ve taught the intro class for our electrical engineering department. And students come in and they’re basically high school students. Um, and then getting to see them after. They’ve gone through the program and there are these extremely competent and sort of independent, you know, scientists is extremely rewarding.

And so the culmination of that, of course, is, the hooding ceremony where, uh, when you graduate a Ph. D. If they come, hopefully they come to the graduation ceremony and you get to be on stage and you get to place the sort of the hood over your student as they sort of officially become a doctor of philosophy, which is, an absolutely wonderful moment.

It is really special and something that that I really cherish. It’s, it’s, it’s a great part of the job.

[00:29:12] Audrey Colgrove: So, how does the story of the cobbler and the shoemaker play into, um, the development of a graduate student?

[00:29:19] Dan Wasserman: You’ve been talking to my students haven’t you

[00:29:20] Audrey Colgrove: Yeah!

[00:29:20] Dan Wasserman:  Um, okay. So, this story is, or, so, well, first of all, the cobbler and the, and the elves for, for, for the listeners who aren’t familiar with this, this fairy tale is a story about, a cobbler, a shoemaker, um, who was down to his sort of very, very last pennies.

[00:29:42] Dan Wasserman: And, facing, you know, eviction from his shop and starvation. And so he, he goes and , he uses the last of his money to buy, the highest quality leather he can, he can find. And, uh, he brings it home and he, he lays it on, his work table. And, and he cuts it into, the proper shape to make, you know, shoes or boots or what have you, right?

Uh, and then he goes to bed. and then when he wakes up in the morning, the elves in the house have fabricated the single greatest pair of shoes ever, ever made and, and he puts them in the front window of his shop and of course a, a passing prince or what have you, you know, sees these amazing shoes and pays him a pretty penny and then he goes and he uses that money to buy more leather and then he puts the, he cuts the leather and puts it out at night and then the elves come out at night and, and, and fix the shoes.

So, I think I first told this story to my research group, when my eldest, uh, child, my son, was, probably two, three, and we were reading fairy tales to him, and so I think I had recently read that story to him, and, my students were sort of setting up experiments and then, Uh, calling it quits for the day.

Uh, and you know, being a PhD student, you have a lot of freedom. You don’t, there’s no time clock. but sometimes you have to, you have to put in a long day and maybe the next day you sleep in or whatnot. But I certainly remember as a grad student, You know, long nights in the lab on one of the things like PhD advisor always told me was you never leave a running like you never leave a working experiment.

If you’re getting data, you stay with that experiment until, until you have all the data, that you need. And so my students were doing this thing where they would, you know, they would sort of wander off once they had the experiment set up and, And then they would come back the next day and it wouldn’t work, right?

And, so, I, I sort of In group meeting that day, I sort of sat them down. I was like, let’s let’s have a fairy tale. So I told them the story of the cobbler and elves and I asked them, you know, could they think of like why I might be telling them that story? And there’s, of course, you know, sort of stunned silence because obviously Professor Wasserman has lost his mind.

He’s just using our group meeting to tell fairy tales. Yeah. Yeah. Yeah. and I sort of erupted and said there’s no bleeping elves

in science uh, there’s nobody that’s going to come out of the walls and do your experiments for you. Um, that’s not how it works. Uh, have to sort of see these things to completion.

So anyway, That became something of a tradition that I, I tell that story, uh, at, at a retreat every and I, I think my older students are good enough not to warn the first year students. So it sort of always comes as a bit of a surprise. Uh, the punchline comes as a bit of

surprise for them.

I don’t know how much my older appreciate Um, it seems to have stuck with them because they told you about it. So,

[00:32:38] Audrey Colgrove: They practically begged us to ask you about it

[00:32:41] Bailey Tibbett: I think it was like a positive rite of passage

[00:32:43] Audrey Colgrove: oh yeah!

[00:32:43] Bailey Tibbett: sort of deal thing for sure.

[00:32:46] Audrey Colgrove: I think they just were desperate to have someone else in the world understand.

[00:32:50] Dan Wasserman: Understand how crazy their professor is

[00:32:52] Audrey Colgrove: I don’t know about that

[00:32:54] Dan Wasserman: Yeah

[00:32:54] Bailey Tibbett: I mean, it’s definitely a, it’s a very true, hard learned lesson for sure. I would say the Ph. D. because I mean, you definitely wish, with all of your might, that the elves are real. man, you know, it would be so nice. I work with bacteria, so it’s like, sometimes it’s just like, I’m waiting for them to grow, like, do I really have to be here?

That sort of thing, or, I know, like, I’m mildly familiar with, like, a lot of your work in tandem with Seth Banks group. So, like, with Molecular Beam Epitaxy and MBE and stuff, so I know those growth days alone can be, like, 18 to 20 hour days. And so It, I think it’s a good way to express a pretty harsh reality.

[00:33:35] Audrey Colgrove: My dad’s favorite story, and I know, I think Bailey’s heard this before, my dad’s favorite story to tell from his PhD is, uh, that he, he dragged a sleeping bag, a jar of peanut butter and a loaf of bread into his lab and apparently spent an entire week there once, um, watching an experiment that just could not be left alone.

[00:33:54] Dan Wasserman: When, when I started my postdoc, I, I, uh, for a variety of reasons, I ended up doing my postdoc at the same place I did my Ph. D. Um, because my wife is also an academic, so we’re always sort of a little bit limited uh, geography wise. But, I got assigned to new office, office as a postdoc. And so I walked into the office my first day as a postdoc carrying my computer, and then I walked back to my car, back to my other office.

And then I walked in with my sleeping bag sleeping mat, . Uh, and the person I shared an office, with, another postdoc who actually ended up becoming a great friend of mine and is actually a, a faculty who I collaborate with. Um, we have all the time. We have a number of programs together. but I didn’t even think much of it.

but apparently he has the equivalent of his cobbler and elves story, which is the story of Professor Wasserman walking into his postdoc office with the first thing with a computer and then the second thing with the sleeping bag. Um, so I guess maybe all professors have some variation of this story.

Uh, I just, I feature in, in his, which is sort of flattering, I guess. Or terrifying.

[00:35:02] Audrey Colgrove: speaking of your kind of, journey, like, specifically your education journey, we, we were wondering if you’d be willing to talk about, um, the fact that you have two undergraduate degrees, one in engineering, physics, and then one in history.

And how, how do you see, like, overlap between these two subjects in your work today?

[00:35:18] Dan Wasserman: I have, so I, I double majored, right? So I have, I have one degree. It’s, a bachelor of, science. but yeah, I also, double majored in, history and specifically in Latin American history. So first of all, I think I think it’s extremely important. for me, at least, to try to be sort of well rounded and and have other interests outside of science.

And when I teach that freshman class in the actual engineering department, , you know, one of the things I always tell the students is that this is probably your last time where you’ll be able to learn for learning sake. and it’s an amazing opportunity because at a school like UT, you have some of the, and I’m a little bit biased here, but some of the best professors in the world, to teach you.

Anything that you might want to know right there. Just the breadth of knowledge and the breadth of opportunities here is extraordinary. And so take advantage of that. don’t just try to take the easiest class that satisfies some, you know, silly flag that the university set up. Like, take something that you’re interested in or something, you know, well outside of, you know, engineering.

you don’t get this opportunity very often. Thank you. for myself, I, did try to do that, when I was an undergrad. I, I, I was engineering physics, but I had interest in history. And, and in fact, I, I, You know, I wasn’t sure that I wasn’t, I was going to go to grad school and in the sciences.

I, I was sort of thinking a little bit about, you know, PhD in history. I was thinking about, I took a bunch of policy classes, um, and I was really interested in public policy. and so I sort of considered, doing a master’s in public policy as well. And even when I was a Ph. D. student, uh, when I was a Ph.

D. student, I took classes at the Woodrow Wilson School, which is a, a policy school at, at Princeton. one of the classes was about, sort of carbon sequestration. And we actually ended up getting to go to the Amazon as part of the class, which was kind of fun. But I also TA’d, I hope my PhD advisor doesn’t listen to this podcast.

I think we’re probably safe because I don’t think he knows that I did this, but I TA’d a sociology class while I was there. I wasn’t getting paid for it. but just because it looked like a really interesting class. and, uh, so I got to TA that, that class. So. You know, to the extent, how does it help me as an engineering professor?

I mean, certainly I’m a better writer for it, I think. but I, I actually think it’s pretty dangerous to sort of approach it from that pragmatic point of view. you know, it can never hurt to know more stuff, but in general, I never sort of. took any of those classes, taught any of those classes because I thought it was going to make me a better engineer.

I think it does, but I did it because I was sort of interested in it. And I think the, you know, it’s good to know more stuff.

[00:38:09] Bailey Tibbett: Yeah, it reminds me of like a very classical school of thought where it’s the ideal scientist is is one who knows science But can also like branch out to other areas like philosophy. I think it’s like really old philosophy, but I

[00:38:24] Dan Wasserman: I think that’s true. And I think actually what we’re seeing today. I think it’s super important that, you know, we, as engineers and scientists, recognize the value of what our colleagues in the humanities or the social sciences are doing, what they are trying to teach the students here at UT under less than ideal circumstances, uh, is, super important, and we would be making a huge mistake if we just said, well, that’s, that’s the humanities.

It’s unrelated to, to the sciences. And I don’t believe that to be the case. And I think skills that you can learn in an English class or in a history class or like supremely important. and make you a better scientist and also more importantly, a better citizen.

[00:39:17] Bailey Tibbett: So I think if we haven’t belabored this point by now, I think something that’s key is, is variety in education as a whole and variety in science, whether it be, you know, variety through looking into other fields or looking into other methods or just being open to new materials. And I guess to tie that back really briefly to the theme of the podcast for this.

Um, season, which is kind of like looking at emerging materials and stuff, looking at emerging materials in science is like, kind of future drivers of technologies. I guess, do you see any kind of, do you see any materials that kind of show this versatility in terms of having practicality, but also being interesting on their own properties alone?

It’s kind of like a really big question. I’m really trying to tie together and it’s like a threat.

[00:40:09] Dan Wasserman: Well, so, it’s possible that, that I may be the wrong person for the season. Uh, unfortunately we’ve already done 49 minutes, so you’re stuck with me. Um, I, I work with semiconductors. Uh, and in some sense, semiconductors are, at least for sort of modern, electrical material science engineering.

They’re, sort of the stalwart material system. so yeah, we’re, we’re sort of getting new tricks out of old dogs. Um, I would say, and you know, we, we, Um, I guess what I would say is that, in terms of emerging materials, the idea of sort of leveraging existing materials and finding new ways to work with them and new ways to put them together, in some ways, sort of gives you you.

new capabilities and, and I guess new materials and it’s, it’s new capabilities with old materials, I guess, is sort of what, my group largely does. And of course we do have some programs, uh, and some collaborations with faculty here. At UT, we’re working with Professor Alex Demkoff, and he grows these really cool titanate materials that we work with.

we work with, Delia Milliron’s group on, using her plasmonic nanocrystal, materials. or we’re, we’re trying to set up a program with Brian Korgel’s group to, to make some quantum dots for us. So, we certainly do get to play around with new materials. But, you know, One thing I will say is that, semiconductors have been around for a long time, and there’s like a reason, uh, why, why they have been around.

And, and, uh, certainly, you know, new materials have, have come and gone, uh, and new fads have come and gone in science, and then ultimately our, you know, computers are still made out of semiconductor materials. Um, It is extremely fun to be able to do new things with old materials, and at the same time, because UT has such a vibrant materials research community, to get to collaborate with all of these amazing PIs and their amazing students, and also get to play with some of the new materials that they’re developing, which is super exciting.

[00:42:23] Bailey Tibbett: Yeah. I know you said like, Oh, maybe I’m not the right person for this podcasting, but honestly, I think like reinvigorating or maybe not reinvigorating new material, old, old materials to new applications is I think that’s perfectly in line with the theme of what we’re to look at. So I wouldn’t worry there.

[00:42:38] Dan Wasserman: Okay you won’t have to burn the tapes then.

[00:42:40] Bailey Tibbett: No, no need to burn the tapes.

[00:42:43] Audrey Colgrove: Well thank you so much for joining us.

[00:42:45] Dan Wasserman: My pleasure this was a lot of fun.