Manu Prakash won a contest to develop the 21st-century chemistry set. His version, based on a toy music box, is small, robust, programmable and costs $5. It can inspire young scientists and also address developing-world problems such as water quality and health. (Credit: Kurt Hickman/Stanford News Service)
Although the original prototype was made from music box parts, Prakash and Korir have many versions in which the crank and pins (they call this part the actuator) were printed on a 3D printer. They say the actuator, the paper tape, and the silicon chip can all be modified to meet different uses, and can be made from inexpensive, durable materials costing less than $5.