Postdoc Spotlight: Dr. Steven Dean

ADELPHI, MD, UNITED STATES

04.25.2016

Story by Jenna Brady 

U.S. Army Materiel Command   

A native of El Paso, Texas, U.S. Army Research Laboratory Postdoctoral Research Fellow Dr. Steven Dean has had a connection to the U.S. Army for as long as he can remember.

Dean's grandfather served in the Army during the Korean War and attended Officer Candidate School at the very location where Dean currently works: Aberdeen Proving Ground, Maryland.

Now, Dean works to support Soldiers as an engineer in the ARL Lethality Division's Energetic Materials Science Branch.

His work falls under the laboratory's Materials Research campaign, whose mission is to perform fundamental interdisciplinary research in materials and manufacturing science to ensure rapid and affordable development of materials, from discovery to delivery, critical to the Army of 2030.

To reach this position, Dean first received a bachelor's degree and master's degree in mechanical engineering from Texas Tech University in 2006 and 2008 respectively. He received a doctorate in mechanical engineering from Pennsylvania State University in 2015, where his research focused on cold-sprayed intermetallic energetic materials. Dean's journey to his career started out with an interest in cars.

"I decided to major in mechanical engineering because I liked cars," Dean said. "I could tell you the horsepower and torque of pretty much every car being sold at the start of the millennium. As I got deeper into the mechanical-engineering undergraduate curriculum, I realized that in many ways, automobiles were a fully mature technology, at least on the mechanical side, but that there were many new frontiers opening up in the field, such as nanotechnology."

After a less-than-inspiring internship at a 3M factory in Brownwood, Texas, Dean decided he wanted to pursue a graduate degree, as the work he did at the 3M plant was all about quality control and the lack of intellectual challenge left him wanting more than to just "work for the weekend."

Dean said his decision to attend Texas Tech University and work for Dr. Michelle Pantoya was the most important factor that led him to his current field.

"Dr. Pantoya's nano-combustion laboratory conducts research on nano-scaled thermites, which are mixtures of aluminum and metal-oxide powders that release a significant amount of energy when ignited and have applications in car airbag inflators, biological-agent defeat and primers in gun propellants," Dean said.

This experience was Dean's first introduction to the field of energetic materials and numerous experimental techniques that he still employs on a regular basis, including high-speed digital videography and scanning electron microscopy.

During his doctoral studies, Dean had the opportunity to work with several ARL personnel as he researched cold spray at the laboratory and at Penn State's Applied Research Laboratory.

"I came to Aberdeen Proving Ground for a review meeting off post, and was able to meet with a member of the ARL cold-spray team while I was in town," Dean said. "That was my first time in the Rodman Building. I remember being very impressed by the facilities available at ARL–APG, something that still occurs to this day."

Dean is currently working on two projects at ARL.

The first is the assembly and characterization of a laser-driven, flyer-plate experiment that will help the Army quickly and cheaply qualify new energetic materials for further testing.

"The development of energetic materials is a complicated and costly process, made more so by the large sample requirement of many tests currently used to determine if a material is worth the effort of further development," Dean said. "By developing a test that only requires milligrams of material, rather than multiple grams, the field of candidate materials can be more quickly winnowed down, which will ultimately lead to faster delivery of these materials to the warfighter."

According to Dean, energetic materials store chemical energy that can be released in a rapid exothermic reaction and have defense-related applications as propellants and payloads in weapon systems.

"As the modern battlefield evolves, new energetic materials will be needed to meet its changing demands," Dean said. "The need for this evolution is most visibly seen in the increased use of both large and small unmanned aerial vehicles as a means of reducing risks to the warfighter in the asymmetric conflicts that are becoming the hallmark of the 21st century."

Dean said the limited payload capacity of these drones—due to their small size or the prioritization of fuel economy over armament—necessitates an increase in the energy density of the munitions they carry. New classes of energetic materials can fulfill this requirement, but before they can be integrated into weapon systems they must be well characterized with accurate models so their performance can be predicted and safe handling procedures can be developed.

Dean said that the flyer-plate experiment is useful in this sense for several reasons.

"First, the amount of material needed to collect useful data is very small, a vital factor when investigating materials that are only produced at a rate of milligrams per day, as some energetic materials are," Dean said. "Second, neglecting the cost of the energetic material being tested, the cost per test is small. Third, the experimental throughput is high, as it is possible to conduct dozens of plate launches in a single day." This combination of small sample requirement, low test cost, and a high number of tests means it is possible to collect enough data that statistics can be gathered on the material's performance, rather than only relying on two or three data points from which to draw conclusions.

Dean's second project involves the use of diamond anvil cells to study the properties of a potential new energetic material at ultra-high pressures.

"The goal of this research is to identify materials that undergo phase changes at high pressure that transform the material into an energetic material," Dean said. "The primary challenge with this process is recovering the material back to ambient pressure while still maintaining it in the energetic phase."

While the laser-driven, flyer-plate test is a quick and cheap way of testing a new energetic material's properties, he explained, the diamond anvil cell can be used to create new energetic materials that will enable decisive warfighter overmatch.

With an extensive history in mechanical engineering, Dean said, nothing compares to the environment that ARL and its workforce fosters.

"Learning from my coworkers is what I like most about working at ARL," Dean said. "I came in to this position with a great deal of knowledge, almost none of it directly related to the projects I've worked on. Being around people with years of in-lab experience has taught me more in 11 months than years of grad school."

Although Dean is a rather new employee, he is greatly inspired by his work and the support that he receives from his coworkers—motivational factors in all that he does.

"I've been given real ownership of my projects," Dean said. "I know that my coworkers are depending on me to succeed, and they're doing all they can to make sure that I do. Knowing that my work will have a real impact on the team's success, and on the effectiveness of our warfighters, makes me excited to come to work every day."

Short term, Dean plans to complete a thorough characterization of the laser-driven, flyer-plate experiment and publish the results in a special issue of Applied Optics journal focused on research at ARL. Long term, he said, he would love to continue working on the development and characterization of new energetic materials as a federal employee at ARL.

Outside the lab, Dean has spent several years developing his skills as a photographer.

"This hobby stems directly from my experience as a researcher," Dean said. "Throughout graduate school, I frequently used high-speed digital video and electron microscopy. These activities showed me the power pictures have to convey information to a wide audience, and gave me a beginner's understanding of how to create a compelling image."

Dean is also passionate about communicating to young people the importance of science, technology, engineering and mathematics, or STEM, education through outreach activities.

"I'm glad I work at a place where opportunities to give back to the community in this way are widely available," Dean said. "I'm active in the PACES program on post, which brings in Harford County eighth-graders and shows them some of the exciting things that are possible in the STEM fields. I was also the instructor for the Cub Scout Engineering badge at last year's STEM in Scouting Day at APG."

As a supporter of STEM education and outreach activities, Dean has a wealth of knowledge and advice that he is always willing to share with members of younger generations who may be interested in a STEM career.

"I would tell young people interested in STEM careers that they're making a wise choice that will pay dividends not just in their future financial success and independence, but also in their enjoyment of life in general," Dean said.

The desire to know how the universe works is fundamental to the human condition, he added, and studying STEM is one way to pull back the veil of the unknown and find out why things are the way they are.

"One of the most compelling reasons to study STEM is that it affords the opportunity to not only understand how things work, it also gives one the tools to improve those things both for yourself and for future generations," Dean said.

When it comes to those who are not interested in a career in a STEM field, Dean has advice for them as well. "I think a lot of people, young and old, are afraid of STEM, and math in particular, because they've had bad experiences with it in the past and have convinced themselves that they're not 'math people,' that their brain 'doesn't work that way,"' Dean said.

Dean noted there are myriad reasons why this is the case, but he thinks one of the most common is that many math and science curriculums do a poor job of showing students why those skills are important to develop.

"Many math and science teachers lack direct experience in STEM fields, and thus can't accurately explain why it is that students need to know how to solve an augmented matrix, or when they'll use the quadratic equation in real life," Dean said. "I used it last month."

Dean said choosing a STEM-related major does not mean that you have to work directly in a STEM field.

"I can imagine a sculptor with a background in structural engineering creating soaring works of art, or an oboist with an understanding of fluid dynamics creating an oboe I'd actually want to listen to," Dean said. "I'd especially love to live in a world where more of our leaders had STEM backgrounds, and were driven to make policy decisions based on factual evidence rather than poll numbers."

For information on ARL's Postdoctoral Research Programs and eight technical campaigns, visit http://www.arl.army.mil/www/default.cfm?page=177 and http://www.arl.army.mil/www/default.cfm?page=172.

• Date Taken: 04.25.2016
• Date Posted: 02.10.2017 13:44
• Story ID: 222733
• Location: ADELPHI, MD, US