Patenting Body Armor

USF graduate is working on a new type of body armor that is both strong and flexible.



By Barbara Melendez

     USF News


TAMPA, Fla. (Sept. 29, 2011) – Military leaders have anguished over the question for centuries: How do you protect soldiers in battle in a way that allows them to move around easily?


Prompted in large part by friends from his hometown in Jupiter, Fla. who are currently serving in the U.S. Army, University of South Florida graduate Dan Miller decided to try to find a solution.


Taking a hybrid approach – combining flexible and rigid elements – he developed a new form of body armor that follows in the footsteps of this age-old quest.   


In 3000 BC the ancient Egyptians wrapped quilting from their armpits to their knees. The Celts developed chainmail. The Syrians in 1400 BC sewed brass scales onto a protective garment. The early Greeks and Romans developed suits recreated in many a classic gladiator film, mixing leather and metal.


Visit New York’s Metropolitan Museum of Art and you’ll find chainmail and suits of armor for soldiers and horses, primarily from Europe and Japan – a sobering reminder that weapons were steadily growing more deadly. The knights and crusaders of the medieval era evolved ever more elaborate – and heavy – metal suits. Over time a smaller protective covering for the chest and back called a cuirass eventually shrank into basic helmets and flak jackets. The bullet-proof vest and other torso-covering shields comprise the modern incarnation currently in use.  


Every era reveals the two most daunting issues armor designers faced.   


“The objective of body armor is to provide an individual with a form of resistance from a specified threat while maximizing the wearer’s dexterity and minimizing the armor bulk,” Miller points out. “All body armor systems share at least one inherent trait, a balance of user mobility and ballistic protection.


Traditionally, as the armor system increases in weight and bulk, the wearer loses stamina and the ability to move rapidly to counter the movements of their adversary. This trend is evident in modern warfare where on the battlefields of Iraq and Afghanistan, United States and Coalition fighters regularly wear hard armor weighing at least 25 lbs. In contrast, their opposition does not typically wear body armor and may only be carrying extra ammunition.”


Miller has addressed both strength and mobility with special attention to where it’s needed most.


“Although the need to protect vulnerable areas is high, the torso and limbs have both proven to be very difficult to protect in past conflicts,” he said. “This brings up balancing mobility and ballistic protection again. To protect the torso and limbs, body armor designers and inventers must balance and focus on flexibility, low weight, and ballistic protection against shrapnel and moderate caliber rifle missiles. This means body armor designers need to devise clever technology to defeat battlefield threats while maintaining low weight and high mission effectiveness. I decided to go the simplest route to achieve the best compromise and the greatest protection.”


The simplest route meant using existing, proven technology – in this case Kevlar® fabric, ceramics and aluminum – and basic engineering principles.


“Naturally, you have to take into account a projectile’s speed, distance, geometry and angle,” Miller said. “It will decelerate and its impact will be distributed as it degrades. My design looks at the effective area – that is, where the impact happens – and distributes the impact to the underlying materials, the protective substrate, to prevent penetration. But it’s also lightweight and moves with the wearer.”  


Miller’s design minimizes the rigid ballistic plate by designing the geometry to be the size of the effective area to handle different types of projectiles. He focused on the best traits of the various existing armor systems and set out to make further improvements. His new armor is a hybrid semi-flexible armor that answers the objective of properly balancing mobility and protection. 


“This is accomplished by using a matrix of specially designed small, rectangular ballistic plates placed on top of a substrate of flexible woven Kevlar® layers. Each plate is reinforced with at least one Kevlar® sheet. The small ballistic plates are secured in place via elastic bands in an over-under cross fashion. To avoid the inevitable gaps caused by using rectangular plates, my armor plates are skewed in two directions to provide a vital gap overlap.”


Computer modeling enabled Miller to simulate the moment of contact looking at impact speed, angle and dynamic (impact) response. He used ANSYS simulation software to complete the finite element analysis (FEA), a very common industry standard.


Miller is a commissioned officer in the U.S. Navy Reserves and is currently working for the Hatch Corporation. He co-authored a textbook, Introduction to Programming Concepts with MATLAB with USF Mechanical Engineering Professor Autar Kaw, recently honored as the nation’s top engineering educator by the American Society for Engineering Education.


“Throughout the process I used principles I learned from Professor Kaw as well as my other teachers throughout college,” he said. “But Professor Kaw is an important mentor whose work is behind a lot of breakthrough research in laminates that’s still used today. He harped on following systematic steps in problem-solving and that kept me from getting bogged down in any one area.”


Miller received the USF Provost’s Teaching Assistant award in April just before earning his Master of Science in Mechanical Engineering (MSME) in May.


“Today working as a mechanical engineer I feel that USF really prepared me on many levels,” he said. “In addition to the core knowledge, my experience with software and even learning about social interaction in this field, have played an important role in my career.”


Ultimately, Miller hopes to see U.S. armed forces and police officers emerging from dangerous situations with their lives and bodies in the best shape possible. His body armor is steadily moving through the patent process with the help of USF’s Division of Patents and Licensing Office.


“They’ve really helped make it a lot easier for me to deal with all the paperwork and hoops you have to jump through,” Miller said. So far he has a provisional patent – an important step to protect his intellectual property.


The get to the next level will take tens of thousands of dollars. Custom made prototypes have to be constructed and then subjected to rigorous government testing before the body armor can be manufactured.


“I have friends serving in Iraq who talked about the difficulty of wearing bulky and heavy armor and being unable to fit in tank turrets and a hard time climbing hills,” Miller said. “I also read articles about this problem from time to time and finally decided I wanted to do something about it.”


For Miller, this is more than a product. It’s a mission. He hopes it won’t be too long before his invention can be used to make the lives of those who risk theirs to protect others both easier and safer.


Barbara Melendez can be reached at 813-974-4563.