Make sure the product you end up using has been tested for biocompatibility and human skin contact for less that 24 hours. Some materials can cause skin irritations so that is why many shin guards have a pad inside to go between the guard and the skin.
You can find this out by using the UL product certification number ( 6 digit number following the UL logo) of the material and search the data base at UL (
http://database.ul.com/cgi-bin/XYV/t...AME/index.htm). This number is entered in the "UL File Number" field. In the certification it will state compliance to ISO 10993 for limited contact, this is what you need.
Good luck and I really like the senior projects that help the less fortunate and extend GP and FIRST into the community beyond robotics.