There's a wonderful story about a Stanford bioengineer who created a remarkable 50-cent microscope. The creator, Manu Prakash, was concerned that poor regions of the world didn't have the technology to detect many diseases that afflicted them. Even more amazing is that this microscope—a bookmark-sized piece of layered cardstock with a micro-lens—only costs about 50 cents in materials to make.
Prakash said, “I wanted to make the best possible disease-detection instrument that we could almost distribute for free. What came out of this project is what we call use-and-throw microscopy." It's not only cheap; it's also nearly indestructible. You can throw it off a building, stomp on it, and dunk it in water, and it still works. Prakash's dream is that this ultra-low-cost microscope will someday be distributed widely to detect dangerous blood-borne diseases like malaria, African sleeping sickness, schistosomiasis, and Chagas. It's a great example of finding a creative way to solve a desperate need.