Concussions are one of the most dangerous injuries to get in a sport especially if that sport is football. Football players who continue to play in a game or practice without knowing that they have a concussion can cause serious damage to their brain. There needs to be a way that football players can know if they potentially have a concussion after a big hit.

My project goal is to design a football helmet lined with rods of the shape memory alloy nitinol that will indicate after an impact to the head whether a football player potentially has a concussion.

I am using the shape memory alloy nitinol in my experiment because of its unique ability to bend back to its original shape when heat is applied. After purchasing long thin rods of nitinol I created a grid that could easily be placed along the interior of a standard football helmet (10 inches tall with 7.5 inch diameter) with the padding removed. Under the layer of metal, I put thick bendable plastic PVC pipes. The padding of the football helmet is then placed over the nitinol grid and PVC pipes. To represent the head in the experiment, I created a 11 pound gelatine mould which is what the average human head weighs. The head was perfectly fitted within the padding. With this unique design in place, when the helmet endures an impact the nitinol is compressed against the PVC pipes from the weight of the head pushing against the padding. The dents that are made in the wire are easy to see and measure. Concussions can occur between 70 - 100 g's. I measured the amount the nitinol bent at different areas of the helmet for impacts that were between 50 g's and 90 g's. With this data, I correlated the amount the wire within the helmet bends to the g-force that was exerted on the helmet by the impact. I tested the helmet by dropping it from a known distance into a large tub of sand. Based on the distance it fell and the depth of the impact made in the sand I was able to determine the g-force of the collision. To remove the dents in the nitinol I would place the grid over a pot of boiling water and let the shape memory alloy do the work. After the nitinol straightened out, it was then ready for another trial of testing.

I divided the helmet into 10 equally spaced areas and recorded the amount the nitinol bent within each area for a specific number of g's. My data showed that as the g-force increased, so did the bend in the wire. I plotted the amount the metal bent to the specific number of g's that the helmet experienced onto a graph and created a trend line that is able to roughly estimate the g force of an impact based on the bend in the wire. For future studies, if this metal were applied to football helmets in practices or in games, after a big collision the medical staff could remove the padding, measure the bend in nitinol, and based off that information be able to accurately estimate the g-force of the collision.