The Accidental Chemist | Ep 95

Intro Voices
Coming to DARPA is like grabbing the nose cone of a rocket and holding on for dear life.

DARPA is a place where if you don't invent the internet, you only get a “B.”

A DARPA program manager quite literally invents tomorrow.

Coming to work every day and being humbled by that.

DARPA is not one person or one place. It's a collection of people that are excited about moving technology forward.

Tim Haynes
Welcome to Voices from DARPA. I'm your host, Tim Haynes. Today we're stepping into the Defense Sciences Office, or DSO, which serves as the incubator for DARPA's most fundamental scientific research. Joining us is Keith Whitener, Ph.D., a DSO program manager and physical chemist. He's applying a deep understanding of how atoms and molecules behave at the smallest levels to tackle some of the military's largest operational and logistics problems, like shattering supply chain bottlenecks for essential materials and rethinking how we provide power and energy on the front lines. But Keith didn't start out with a grand plan to reinvent military logistics. His journey to the leading edge of defense science began, quite literally, with a wake up call.

Keith Whitener
When I was in high school, I slept through the AP chemistry exam. I thought it was at noon and it was at 8:00. I woke up to a whole bunch of missed calls on my phone, and basically what happened was I had to start in basic chemistry when I got into undergrad because I didn't have the credits to get out of it.

And it put me in a course with a guy named John Boland. Fantastic scientist, great teacher, great professor. He was also a chemical physicist, and he taught chemistry from a sort of physics based point of view. And I loved it. I was like, if this is what chemistry is, I'm going to be a chemist. I signed up, that was my major that day, and I started taking chemistry classes. I did fine, but I didn't love a lot of the chemistry classes that I was taking. But I was like, you know, at some point this is going to pick back up and it's going to circle back around. It's going to be what Professor Boland was teaching us. Yeah, that was all physics that he was teaching us. He swindled me into becoming a chemist, I suppose. I've always loved physics. I've always loved that aspect of really getting at the nitty gritty of why things work at a fundamental level.

Tim Haynes
That freshman chemistry class sparked a lifelong interest in physical chemistry, a discipline that sits right at the nexus of several scientific fields.

Keith Whitener
So there's actually this debate in the community. It's probably a tongue in cheek debate between what is chemical physics versus physical chemistry, and what's the difference there? In my opinion, what makes the most sense to me is chemical physics is the physics of atoms and molecules. Right. So how they move, how they interact, what their dynamics are at a very sort of fundamental level, physical chemistry is trying to pull in concepts and principles from physics and apply them to chemistry.

I kind of joke that physical chemistry is I wasn't good enough at math to be a physicist, but I wasn't good enough in the lab to be an organic chemist, so I just kind of fell in the middle.

Tim Haynes
When Keith says he fell in the middle between two disciplines, that's usually an asset, not a liability, at least here at DARPA. Time and time again, we see revolutionary ideas in science emerge from the spaces between traditional ways of segmenting the world. His interest is in seeing ideas from every angle, in this case seeing not just the observable properties of chemicals, but how they're structured at the quantum level.

Keith Whitener
At least for me, the more physics that I study, even now, the more I enjoy it, you know? And it's fascinating. See, all the connections between chemistry is essentially a subset of physics. And so at the most fundamental level, everything chemical is driven by physics and particular by quantum mechanics. Right. So if you take a quantum mechanics class, one of the things that you will do in that class is solve the equation for the hydrogen atom, for example.

Tim Haynes
Keith is referring to Nobel Prize winning physicist Erwin Schrödinger, who's famous in pop culture for his Schrödinger's cat thought experiment. But in scientific circles, his most notable legacy is Schrödinger's equation, the foundational mathematical framework for quantum mechanics, which describes how matter and energy behave over time at the smallest possible scale.

Physics uses the equation to predict how particles will behave. Chemistry uses it to explain why and how atoms stick together. For instance, it explains why pure water is H2O instead of H3 zero. For the last hundred years, the equation has helped bridge different ways of seeing and understanding the universe. Now back to Keith. Solving the Schrödinger equation for hydrogen.

Keith Whitener
It's one of the few cases in quantum mechanics where you can solve a problem and get an actual definite answer on pencil and paper without having to use a computer or something like that. But everything kind of goes from there, right? Other atoms are governed by the Schrödinger equation. And so molecules, everything else, it all flows from there. You know, a lot of chemistry, a lot of physical chemistry that goes on derives from, well, let's see what quantum mechanics tells us is going to happen if we do this to a chemical, right, if we hit it with a photon, or if we make this bond vibrator, if we do special things to it to try to make interesting things happen.

Tim Haynes
For Keith, the desire to make interesting things happen by engineering the elements at an atomic level became the focus of his career. It led him, through a PhD at Yale, studying the spectroscopy of fullerenes, tiny cage like molecules made of carbon, often called buckyballs. After completing postdoctoral work at the University of Colorado, he took a role at the Naval Research Laboratory, or NRL.

It's the government research group focused on maritime innovation for the Navy and Marine Corps. After over a decade at NRL focused on researching 2D materials like graphene, he reached out to an old mentor for career advice. That mentor told him that he belonged at DARPA.

Keith Whitener
I had that feeling that I feel like other PMs have to have had, this feeling at some point where they're like, no, I am not DARPA material. You know, it's a huge imposter syndrome. We all grew up with DARPA being this huge, crazy thing where you do insane projects. And I thought, that's ridiculous. And he was like, no, no, no, no, no.

I know bio is not really your thing, but, you know, DSO does a lot more chemical physical type research. Why don't you talk to the director there who was Jinendra Ranka at the time, and I did. It was funny. I hung up the phone and then 30 minutes later he called me and he was basically like, 'Pitch me a program,' in not so many words. And I essentially pitched the idea for ExCURSion, and the rest is history.

Tim Haynes
We'll hear more about ExCURSion later. It's part of Keith's portfolio of programs here at DARPA, where he's seeking to reshape logistics and the tactical capabilities of the US military. The best way to understand how he applies his physical chemistry expertise to national security is to look at a program called SeREne, which stands for Switchable Reactives and Energetics. The program tackles a fundamental chemical trade off in munitions design the balance between safety and raw power.

Keith Whitener
SeREne is essentially an engineering program for explosives. Specifically, we don't want to make new explosives. We want to take the explosives we have and imbue a new capability in them. There was a joint force program that started, I guess, back in the mid to late 2000 and extended for several years, where they were looking at making munitions that were really, really, really hard to set off the idea. Obviously being that if you're shipping around munitions, if you are under fire, things like that, munitions can get hit by shrapnel, they can catch on fire, they can do all sorts of stuff and they could easily go off.

You can imagine that is bad for bombs and rockets and things like that. And so there was a big push to figure out ways to make it so that munitions were really, really desensitized to those types of insults. And so that actually went pretty well. They were able they have all of these tests that they do for insensitive munitions. It's one of the mil standards where they shoot shrapnel at it and they shoot a slug at it, and they have a shape charged and they set them on fire. And they do all sorts of stuff, drop them off a building and whatnot, and just make sure that they don't they don't go off. However, one could think it would be really nice since we want munitions to be really, really safe for 99% of their life and then really, really powerful for the last one or less than 1% of their life.

Can we switch back and forth between those two states or really, say, a state and a really powerful state? And then it evolved from there and we said, can we tune it? Can we tune the size of the explosion that we want.

Tim Haynes
To make explosives both safe to transport and tunable on the fly, SeREne leverages a physics insight from one of Keith's performers on the program, Los Alamos National Laboratory, regarding how shockwaves propagate through materials.

Keith Whitener
The Los Alamos breakthrough, where you can structure the material in a way where there's a lot of essentially there's a lot of air gaps that break up the shock. And the reason for that is because the shockwave is a sound wave, essentially, and sound travels at different speeds through different materials, travels at vastly different speeds between condensed materials like solids and liquids versus air. And so if you have a lot of air gaps in your material, the shockwave tends to fail because it travels really quickly through the solids. But the other portions of it that are traveling through the air can't catch up. And so you just dissipate energy quickly. If you fill in those air gaps with water, you have now essentially matched acoustic impedance between the solid and the water.

And because solid liquid sound waves are fairly similar in velocity. Right. And so now the shockwave can flow much more evenly through the material and can actually sustain a detonation. We've been poking around at it ever since. And so you can actually there's at least some indication that you can kind of half fill it and you'll get half the explosion, quarter fill it and quarter the explosion like that. And so hypothetically, it could be continuously tunable, which could be really cool.

Tim Haynes
While controlling the explosive yield of a weapon could change how the military fights, Keith is also working to ensure the military has the materials it needs to build energetics in the first place. Nitric acid is a chemical critical for building explosives as well as for fertilizing the global food supply, but its production is increasingly being seen as a supply chain risk.

Keith's HNO3 program stands for high efficiency nitrogen oxygenation. It's also the chemical formula for nitric acid. The program explores ways to quickly and affordably produce nitric acid using just air and water, and to do so at the point of need. Keith Whitener
Nitric acid is important in a couple of different ways. So about 80% of the nitric acid that we use right now goes into making fertilizer. And about 50% of the global food supply uses some sort of nitrate fertilizer. So it's very important from that point of view. It's also important because it's a really good oxidizer. And you can use it to make explosives, and you can use it to make propellants. So it's useful in that sense from a military point of view.

Tim Haynes
Nitric acid processing has been basically unchanged for decades. It requires massive manufacturing facilities concentrated domestically in just a handful of locations, often relying on ammonia imported from overseas.

Keith Whitener
You can get nitrogen from the air, and in fact, that's how it's made. Now you make it by making ammonia first and then oxidizing ammonia. But it should be more energy efficient to just make it directly instead of going through ammonia. The nitrogen that exists in the air is N,2 dinitrogen. That bond that binds those two nitrogen atoms together is one of the strongest bonds in chemistry. So it's very, very difficult to break. And it turns out that to go from N2 and oxygen and water to nitric acid, thermodynamically, it doesn't take that much energy. The elevation change in the energy landscape is not very high, but there's a huge barrier to get there. And there's been a ton of work over the past, probably several hundred years at this point, trying to figure out how to get over that barrier.

It's a really, really interesting place to be in terms of chemistry. It's just a really hard problem. And so from a basic point of view, that's kind of where our motivation stands to go after HNO3. From an applied point of view, obviously it's very, very useful.

Tim Haynes
Beyond HNO3, Keith is applying the same point of need philosophy to a problem that dictates not just what we can build, but if we can fight it all. Fuel logistics moving liquid energy from refineries across oceans into contested environments, and finally to the front lines is one of the most dangerous and expensive operations in the world. And the US military consumes a tremendous amount of energy: roughly 10 million gallons of fuel per day.

Keith Whitener
Getting that amount of fuel everywhere it needs to be. Every day, 365 days a year is an enormous undertaking. And so if you had the capability of having fuel when you need it, as long as you have some sort of energy source to make that fuel, that could be incredibly powerful, dramatically simplify fuel logistics. One of the big issues with fuel logistics is that most of the injuries and casualties that happen in modern warfare, Operation Enduring Freedom or Operation Iraqi Freedom, happened because of logistics supply lines getting attacked, right. Those convoys are very, very vulnerable. And so if we could make things at the point of need and avoid those supply lines, that would be a huge sea change. Supply lines have been attacked since the Peloponnesian War, right. There is a long history of doing exactly that in order to isolate forces. If we can obviate that, and that becomes a huge strategic and tactical advantage.

Tim Haynes
Keith's ExCURSion program, which was mentioned earlier, stands for Expeditionary Carbon Utilization for Energy Resilience and Stabilization. ExCURSion aims to bypass supply lines almost entirely by generating energy at the point of need in the field.

Keith Whitener
So when I came in to DARPA, I had this grand vision, which is what I initially wanted Excursion to be, which was you have a box that functionally looks like a battery, but it has the energy density of a fuel tank. It's a big problem in portable power sources like batteries or fuel or things like that, is that batteries are really useful.

They're electrically rechargeable, at least in theory, but they don't have the energy density that fuel does. So that's why we use so much fuel, because we need lots and lots of energy. Fuel, on the other hand, you have to refuel, right? You have to resupply fuel. We wanted to focus on the hardest scientific problems first. And so the hardest scientific problem is to turn CO2 into something useful. And that's what ExCURSion ended up becoming. We had a lot of success with that program. And so now the next step is go back to my grand vision, which is ExPEDitions.

Tim Haynes
ExCURSion is still underway, but so far, Keith's performers have demonstrated that it's possible to create fuel cells with enough energy density to provide mission endurance and range comparable to fuel based systems.

Keith is using the efficiency of rechargeable carbon air energy systems, shown in ExCURSion as the baseline for his latest program, ExPEDitions. ExPEDitions is short for Expeditionary Power and Energy Dense Implementations.

Keith Whitener
Energy is like the size of your bank account, and power is essentially how fast you can spend it. So for some applications you want a lot of energy, but maybe low power. So a drone cruising over the Pacific, spending energy at a fairly slow rate, but you need a lot of energy to cross because it's a big ocean.

You know, in other applications you'll need a lot of power, but maybe not so much energy. So like a single, really high power laser shot, something very quick. You can spend a lot of energy quickly, but you don't need a ton of energy overall. Building a system or battery or fuel cell or something with the best of both worlds, high energy and high power is is a very difficult problem.

That's actually what the ExPEDitions program is going after. Let's make a battery with the energy density of fuel. But with all of the sort of operational flexibility and versatility of batteries. So being electrically rechargeable and pumping out electrical energy, which is much, much more efficient than the type of energy you get from an engine, which is mostly thermal energy.

Batteries are silent, batteries usually have a pretty good thermal signature. And so there are a lot of reasons that the military might be interested in batteries. And if they had an energy density on par with fuel, then using fuel honestly wouldn't make a ton of sense. You would need a way to get energy there to charge all your batteries, but after that, you have a system that's more efficient, it's quieter, and it's more versatile.

So that's kind of the big goal. And that's the goal of ExPEDitions, which is my newest baby, which I'm really looking forward to.

Tim Haynes
Keith's ability to think broadly and solve tricky problems isn't just limited to the intersection between physics and chemistry. The curiosity and quick thinking that led him to DARPA were broadcast to the world years earlier, when he decided to take a shot at one of television's most famous trivia challenges.

Keith Whitener
So after I had moved from Colorado, I was living with my now my in-laws for a brief period of time before our apartment got ready in D.C. and they would always watch Jeopardy every night. And so I was sitting there and we were playing along, and I was answering a bunch of the questions like, you're really good at this. You should try out for it.

No, no, no, no, no. And finally, my wife said, listen, you need to try out for this. That's all I want for Christmas. I don't want anything else. Just try out for Jeopardy. We'll see what happens. So I didn't take the bait. I did actually buy her something. I bought her a backpack, but then I had taken the online test that they had for Jeopardy, and I'd put the confirmation form in the backpack.

Jeopardy Announcer
This is Jeopardy! Please welcome today's contestants. A research chemist originally from Charlotte, North Carolina, Keith Whitener.

Tim Haynes
Keith won seven episodes in the regular season and competed in the Tournament of Champions, providing correct responses on everything from pop music and Italian art to astronomy and medieval warfare.

Keith Whitener
And then they invited me on a few years later on this. I forget what they called it, like battle of the decades or something like that, where they had people from the 80s and 90s. Ken Jennings was there and Brad Rutter was there, and all sorts of other folks. I got smoked, I got annihilated at that time. But yeah, it was it was a lot of fun.

Tim Haynes
If you want to see how you stack up against Keith on trivia, we've shared links in the show notes.

Keith Whitener
So there is a distinct tie that I found between Jeopardy! And there's a lot of wordplay that goes on in Jeopardy, and I feel like that really serves me well when I'm trying to come up with with acronyms. But I take a lot of pride in my acronyms. I was especially proud of HNO3. It's High Efficiency Nitrogen Oxidation.

And so if you go through and you look at the number of O's, there's one in nitrogen and there's two in oxidation. So there ends up being three O's in there.

Tim Haynes
Beyond fun program acronyms. Keith's creativity and enthusiasm continue to drive new ideas at DARPA, where he routinely collaborates with a highly diverse group of scientific experts to push the limits of what's possible.

Keith Whitener
It's fantastic. I mean, I adore my fellow PMs in DSO. It's really cool because we can have out-there ideas and we can shoot them down because, you know, for instance, I had an idea about quantum mechanics and then I floated it by Mukund and he was like, absolutely not. And then a couple of weeks later, he's like, there might be something there.

And so I get to throw really, really crazy ideas at the wall and get to have other people shoot them down. And then if they can't, I get to say, hey, maybe it's maybe it's actually a good idea. It's almost never a good idea. But it's, you know, there's at least a glimmer of hope there.

Tim Haynes
In the Defense Sciences Office, the line between science fiction and reality is incredibly thin. By asking fundamental questions about how atoms rearrange and how energy transfers, program managers like Keith Whitener are helping to create the future of national security. To learn more about the SeREne, HNO3, ExCURSion, and ExPEDitions programs, and other incredible work happening across the agency, check the show notes for links or visit darpa.mil. Thank you for listening to Voices from DARPA.