This chapter contains five engineering case studies. Each one presents an engaging story of how engineering was used to find a solution to a real-world problem or opportunity. The stories were chosen to span a range of science and engineering fields. The case studies might be used in the classroom to help introduce students to engineering concepts, as a starting point for a larger research assignment, or simply as discussion starters. The stories are: Cardeon: The Rise and Fall of a Medical Startup; Keeping Fallingwater From Falling; Pay-As-You-Go Solar; Makers; and Zapping Trash. A materials list, teacher background information, assessments, and outcomes are provided. This book selection includes the Table of Contents, Introduction, Contributors, About the Authors, References, Image Credits, and Index.