Microelectromechanical systems, or MEMS, are a crucial, yet little understood part of our everyday lives. MEMS are very small devices which can be found in printers, air bags, smartphones, game controllers, TVs, and many other types of household items. This STEM unit will introduce students to the world of MEMS through a very important type of MEMS – the accelerometer. An accelerometer is a device that measures accelerations. Many smartphones have a 3-axis MEMS accelerometer which is used to determine the phone’s physical position. The accelerometer can detect when the phone is tilted, rotated, or moved. Students will construct a large scale accelerometer out of common items and then they will be asked to consult for an athletic gear company concerned with the increasing number of concussions in athletes. Students will need to provide the company with a prototype of a small and sensitive accelerometer to be placed in the headgear that will be able to sense the extent of the impact. MEMS are manufactured through the use of nanotechnology, so students will next explore various techniques, such as silicon etching, by which nanotechnology creates these tiny devices.