Walter Stanley Friauf, 93, died peacefully on Tuesday, October 5, 2021 in Bethesda, MD. Born December 28, 1927 in Pittsburgh, PA to the late James Byron and Helen (nee Cox) Friauf, Walt spent most of his youth in Milwaukee, WI and Arlington, VA, where he graduated from Washington-Lee High School. Walt received a bachelor’s degree from MIT and a master’s degree from U. VA. (1964), both in Electrical Engineering. Before graduation, he and his brother rode their bikes across the United States, an accomplishment documented by Adventure Cycling in a 2014 article entitled, Early 20th Century Crossers: Images of cross-country cyclists from the first half of the 20th century. Early in his career, Walt worked in the engineering departments of the Santa Fe and Southern Pacific Railroads, becoming Assistant Signal Supervisor on the Houston Division of the Southern Pacific, now part of the Union Pacific system. In the Korean War, he was a platoon leader in the 2nd Engineer Combat Battalion, 2nd Infantry Division. Later he was a senior engineer and section chief at an early electronics firm, where he worked on early transistorized implementations of a seismic system and an analog-to-digital converter. Because of a strong aversion to military electronics, which was becoming a primary focus of the work, he left and joined the Electrical and Electronic Engineering Section of the Biomedical Engineering and Instrumentation Program at the National Institutes of Health (NIH) in 1962, and became chief of the section in 1969. Among his noteworthy accomplishments at NIH, Walt designed a wide variety of custom analytical and medical instruments, leading to 40 publications, 11 patents and he participated in over 100 procedures on human patients in the operating room as a member of the Photo-Dynamic Therapy Team. While at NIH, he taught two courses on electronic instrumentation in the Foundation for Advanced Education in the Sciences program. After retiring from NIH in 1995, he wrote a textbook Feedback Loop Stability Analysis published by McGraw-Hill. Walt lived in Bethesda, MD since 1966 and led the Adult Forum at Christ Lutheran Church for a number of years. He and his wife bought an organic hobby farm in central Virginia in the early 1970’s where he spent many weekends and vacations there with family and friends. His hobbies included pets, collecting and restoring old toy electric trains, building dollhouses, and contra dancing. Beloved husband of the late Ida Harris Friauf, Walt is survived by his son, Kenneth, Ken’s children, Christopher and Marie, and Ken’s wife, Anjanette; and Walt’s daughter, Linda, her husband, Paul Fischetti, and their children Grace and Anthony. Graveside service at Monticello Memory Gardens in Charlottesville, VA will be private, but a broader on-line event will be planned in the future. In lieu of flowers, please send donations to the Nature Conservancy’s Memorial Gift ( https://preserve.nature.org/page/81523/donate/1)