Section K
REFLECTION ON THE DESIGN PROJECT
Problem Identification and Justification:
When the team initially started this project, there was no clear direction besides “improve ballistic vests. It wasn’t until after several days of researching articles that a common problem of body armor became apparent. The team discovered that often times body armor is uncomfortable to wear for extended periods of time and that often discourages police officers and soldiers from wearing it. The team wanted to solve this issue, particularly for vests worn by police officers, and found 14 articles justifying the problem statement. These sources consisted of market size estimates and predictions for body armor, editorials written about officers and soldiers who suffer from injuries caused by wearing body armor, surveys taken by soldiers and officers about the downsides of body armor as well as a description about the purpose and use of body armor published by the Congressional Research service. All these statistics pointed towards a common theme of simple issues with body armor, such as comfort, that were being overlooked.
Reflection:
A significant amount of time was spent researching the dangers and issues of modern body armors so that the team could identify the problems that were most important. Much of this time was spent looking at and reading articles on the problems that current body armors face. The team does not regret this time spent because it allowed them to have a clear problem statement that they could work towards resolving.
Initial Research (Review of Patents and current vests):
After determining the primary issues plaguing body armor, the team began to research prior attempts. At first, the team primarily researched existing patents for body armor designs and systems that helped solve our design problems. However, there were many patents that were only indirectly related to our design problem and the team had to change its focus to existing solutions. General research was conducted about the history of ballistic vests, starting from the early 1900’s with flak vest designs. The team then conducted more in depth research about the history and development of body armors since the Vietnam war. The team then examined modern body armors used by the military as well as local police forces. Highly influential in our later design process were the Improved Outer Tactical Vest (IOTV) as well as the Uniform Vest carrier. The team wanted to expand the protection of current vests, much like how the IOTV expanded protection over its predecessor, the Outer Tactical Vest (OTV). The team also wanted to mirror the non-threatening appearance of the Uniform Vest Carrier, which was designed to look like a standard blue police uniform instead of a black, tactical looking vest used by many police officers today, such as the assault vest that our SRO would use.
Reflection:
A significant amount of time was spent researching patents and prior attempts, more time than the team would have liked. Much of this time was spent trying to find relevant patents, as there were many results that only touched on the primary design problems. However, the team does not regret this time spent, because proper and in-depth research was critical to everything from creating the initial design, refining the design, and formulating a process to make a prototype.
Generating Criteria:
After further examination of the articles and research papers, the team outlined the several major problems the documents commonly outlined. From there, the team began to break each issue down into concise and solvable problems which formed the basis of the design criteria.
Reflection:
This section was not particularly time-consuming, but it was imperative for the team to create clear and relevant criteria that we could easily refer to when designing the prototype. However, a few of the criteria were ultimately never addressed as the team had to frequently narrow the scope of the design problem over the course of this project. We eventually realized that not all criteria could be addressed if the team wanted to effectively solve the other design criteria. The team would still like to address these issues in the future given enough time and funding, but for now they serve as a reminder of how important it is to keep the project scope narrow.
Initial Brainstorming:
Initially, each member generated 3 different ideas for a complete prototype that would meet each and every criteria. Nine different concepts were presented and the team began examining them. However, it soon became apparent that some designs were better at meeting some criteria than others. The team realized that each criteria would have to be considered individually, and a method for meeting each criteria would have to be independently determined. The team reasoned that the best prototype design would be one that incorporated the best solutions for each criteria. The team then created decision matrices for each major aspect or criteria of the vest that we needed to solve. The team attempted to make the categories for the decision matrices as objective as possible and pulled data from many different websites to determine values for the decision matrices.
Reflection:
The initial brainstorming of the original nine designs was never put to use. Because of the quantity of criteria and aspects that had to be considered it was unwise to attempt to create a single design that attempted to address them all at once. Once the team broke down the overall vest design into its components, it was much easier to develop solutions that solved the criteria effectively. In the future, the team would immediately begin with brainstorming each criteria individually and then address the issue of combining each solution to create a viable initial design.
Further Research and Final Design Selection (Interviews and body armor survey):
After developing a finished design using the best components from each decision matrix, the team brought the design to our SRO, who gave us high quality feedback about concerns he had with the vest as well as aspects that he thought was promising. The team then wanted to confirm this information with feedback from another police officer. Lieutenant Taylor of the Franklin Police Department was then contacted by e-mail and interviewed about the design of the vest. Although there was initially some miscommunication about the functions of the different components, the team did eventually receive very good feedback. Both interviews confirmed the problem statement but the officers were conflicted about several key points of the design. In order to ameliorate these concerns and obtain more high quality feedback, the team decided more that more input was needed. To get a broader understanding of what the average police officer would like in a vest, the team created a survey and asked Lieutenant Taylor and Sergeant Culp to distribute the survey. The team used the wealth of responses to help better guide the process of refining the prototype as well as determine which aspects of the design to prioritize over others.
Reflection:
The team spent a lot of time getting into contact with the officers and interviewing them individually. Ultimately the disparity in the preferences of the officers led the team to create a survey to get data that more accurately reflected the preferences of police officers in general. Creating the survey was a very lengthy process, as it was necessary to create a survey that was short, but still provided crucial and high quality feedback. The team also spent a lot of time, refining, condensing, and rewriting the questions in order to ensure that the questions were unbiased and easy to understand. The survey was a critical part of this section of the project however because it was the basis of many of the decisions the team made for the rest of prototyping process. In the future, the team would skip directly to creating a survey because while the personal interviews with officers were helpful, the survey provided much more useful feedback and took less time to create and distribute.
Creating the Physical Prototype:
After the design was finalized the team set about creating the first prototype. This involved a lengthy process of finding the fabric necessary, straps required, as well as the kevlar we wanted to use in order to model the vest. The prototype was fitted to a single person, like a standard ballistic vest would be, so the first prototype was made almost purely to see if our measurements were correct. After testing and correcting the measurements, the team set about creating the second, final prototype. Since this prototype was intended to be tested, the team found someone with more experience in creating clothing that was willing to create it. After receiving the created prototype, the team moved on to testing.
Reflection:
At first the team attempted to create the prototype entirely by ourselves. But it soon became apparent that no team member had any experience or skill with sewing and tailoring garments. The group’s mentor suggested to outsource this part of the project to a professional seamstress or tailor, much like how an engineering firm could outsource parts of a project to other companies. The team learned that outsourcing was critical to staying on schedule, especially for a project with such a wide scope. However, this doesn’t mean that the team could simply forget about the outsourced part of the project. The team learned that constant and clear communication was necessary to ensure that the carrier was made to fit our strict specifications.
Making the Shear-Thickening Fluid:
Synthesizing a shear-thickening fluid was the original focus for this project, long before the team conducted initial research for common problems with body armor. This section of the project turned into a miniature version of an entire engineering thesis project, as it took up nearly 4 months of the project time and required its own separate research and documentation. Towards the end of the first semester, the team began researching various scientific articles and research papers pertaining to the qualities of different shear-thickening fluids as well as how to synthesize and apply various shear-thickening fluids. This research process continued for the remainder of this section, even after the team had begun making the shear-thickening fluid. By the beginning of the second semester, the team had gotten into contact with Dr. Van Patten, the head of MTSU’s chemistry department. He graciously let us use his lab and equipment, and offered guidance and advice throughout this entire section of the project. Synthesizing and applying the shear-thickening fluid itself took just under one hundred days, with the team working on it after school hours almost every one of those days.
Reflection:
This section was a major part of this engineering project and took up more time than any other part of the project. After spending several months in the lab it became clear that synthesizing a shear-thickening fluid was worthy of its own thesis project. In fact, Dr. Van Patten frequently opined that a truly in-depth analysis of the myriad of ways to create a shear-thickening fluid could take years, not to mention the amount of time it would take to research a variety of methods of applying a shear-thickening fluid to Kevlar or even some other ballistic fabric. The idea of using a shear-thickening fluid to improve ballistic armor was the inspiration for this project, and the team did not want to let it go, but the team could have saved a wealth of time that could have been spent on other aspects of the project it we had narrowed our scope and abandoned the idea of using a shear-thickening fluid. Though it took up so much time and resources (namely money) the team believes that this is where we learned the most about the engineering process. This single aspect required the team to contact and work closely with a professional in the field of Chemistry, how to analyze and interpret data from varying sources, how to apply that information to a real-life process of making a shear-thickening fluid, how to create a schedule and stick to it, how to deal with setbacks when working with a very rigid schedule, how to document our process thoroughly so that we could perform it repeatedly, and how to improve on steps of the process as we made more batches of shear-thickening fluid.
External Feedback:
The external feedback was entirely positive. The score the team received after review by several judges at the expo was 9.5/10. Other feedback received came from mentors. The content of the feedback the mentors gave was mostly positive, although there was some critique with regards to certain parts of the design (e.g. too military-looking, etc).
Reflection:
The feedback was probably the longest-running part of the project, purely because the team was constantly seeking and receiving guidance from others. After the initial design and survey it became clear that the team would need to seek help from people with years more experience in the field than each member had. This aspect of the project allowed the team to do the project much more effectively than they would have been able to had they not sought the help of others.
STEM Applications:
The team utilized key concepts of stem in order to create and refine the prototype. The most important concept used was the Engineering Design Process. The team carefully went through each step, revising where necessary, in order to make the prototype. STEM Applications were especially important in the formulation of the shear-thickening fluid and in the testing, where the team was required to calculate and account for many variables in order to conduct them properly.
Reflection:
As a result of the overwhelming requirement for the application of STEM principles in the project, the team was able to easily use key STEM concepts throughout the process. The team learned many things about the chemistry involved in the creation of the shear-thickening fluid as well as the many difficulties that can arise in the creation of a product. This section was critical for determining the success of the project, as it allowed the team to proceed through the design and creation of a prototype in a manageable way.
Testing:
The team conducted several tests to determine how effectively the prototype conformed to the criteria. However, due to time constraints and the nature of the criteria, the team was not able to conduct each of the criteria individually. Tests were created that would encompass several criteria at once, and much of the feedback was qualitative. The Usage test for instance, tested the criteria of mobility, weight distribution, flexibility, durability, and snugness. During the test, Sergeant Culp, who wore the vest, was asked to comment on all aspects for both the prototype vest and the control vest while he was wearing each one. The team believes that this categorical approach was sufficient to get quality feedback for each criteria and determine how the prototype vest compared to the control vest in each criteria category.
Reflection:
Because of the time constraints the team faced (due in part to the length of the other sections of this project) the team had to test for multiple criteria in each test. The team would have liked to test for each criteria individually, with much more in-depth and rigorous tests as well as perform these tests with multiple officers. The team learned that documentation is critical when conducting tests, as it is necessary to prove beyond doubt that a prototype meets the criteria set for it. We believe that the tests we conducted do adequately show that the prototype meets the criteria, as well as outperforms the control vest in each criteria category, but having more tests as well as multiple control vests would provide more data points to better prove the superiority of the prototype. This section of the project was critical for determining the success of the prototype and ultimately the team would have liked to spend much more time on this section on the project.