Leland Clark
Leland C. Clark Jr. (December 4, 1918 – September 25, 2005) was an American biochemist born in Rochester, New York. He is most well known as the inventor of the Clark electrode, a device used for measuring oxygen in blood, water and other liquids. Clark is considered the "father of biosensors", and the modern-day glucose sensor used daily by millions of diabetics is based on his research. He conducted pioneering research on heart-lung machines in the 1940s and '50s and was holder of more than 25 patents. Although he developed a fluorocarbon-based liquid that could be breathed successfully by mice in place of air, his lifelong goal of developing artificial blood remained unfulfilled at the time of his death.