Students further their understanding of the engineering design process while combining mechanical engineering and bioengineering to create assistive devices. During this extended activity (seven class periods), students are given a fictional client statement and required to follow the steps of the engineering design process (EDP) to design a new wristwatch face for a visually impaired student at their school. Student groups share their designs with the class through design presentations. A successful design meets all of the student-generated design requirements, including the development of a new method of representing time that does not require the sense of sight. Through this activity, students design, construct and iterate classroom prototypes of their watch designs.