Paperfuge

Stanford bioengineers, including Manu Prakash and Saad Bhamla, have created a human-powered centrifuge that separates blood into its individual components for 20 cents of paper, twine and plastic. Called the Paperfuge, it's part of their effort to develop low-cost tools (which they call "frugal science") that can be used where electricity is not an option.

http://news.stanford.edu/2017/01/10/whirligig-toy-bioengineers-develop-20-cent-hand-powered-blood-centrifuge