Willis Whitfield, Clean Room Inventor, Dies at 92 The enemy was very small but it was everywhere. World peace, medical advancement, iTunes - all would eventually be threatened. Half a century ago, as a rapidly changing world sought increasingly smaller mechanical and electrical components and more sanitary hospital conditions, one of the biggest obstacles to progress was air, and the dust and germs it contains. Stray particles a few microns wide could compromise the integrity of a circuit board of a nuclear weapon. Unchecked bacteria could quickly infect a patient after a seemingly successful operation. Microprocessors, not yet in existence, would have been destroyed by dust. After all, an average cubic foot of air contained three million microscopic particles, and even the best efforts at vacuuming and wiping down a high-tech work space could only reduce the rate to one million. Then, in 1962, Willis Whitfield invented the clean room. "People said he was a fraud," recalled Gilbert V. Herrera, the director of microsystems science and technology at Sandia National Laboratories in Albuquerque. But he turned out to be right. Mr. Whitfield, who worked at Sandia from 1954 to 1984, died on Nov. 12 in Albuquerque. He was 92. The cause was prostate cancer, his wife, Belva, said. His clean rooms blew air in from the ceiling and sucked it out from the floor. Filters scrubbed the air before it entered the room. Gravity helped particles exit. It might not seem like a complicated concept, but no one had tried it before. The process could completely replace the air in the room 10 times a minute. Particle detectors in Mr. Whitfield's clean rooms started showing numbers so low - a thousand times lower than other methods - that some people did not believe the readings, or Mr. Whitfield. He was questioned so much that he began understating the efficiency of his method to keep from shocking people. "I think Whitfield's wrong," a scientist from Bell Labs finally said at a conference where Mr. Whitfield spoke. It's actually 10 times better than he's saying. Willis James Whitfield was born in Rosedale, Okla., on Dec. 6, 1919. In addition to his wife, his survivors include his sons, James and Joe; a sister, Amy Blackburn; and a brother, Lawrence. Mr. Whitfield became fascinated with electronics as a young man and received a two-year degree in the field after high school. He served in the Navy late in World War II, working with experimental electronic systems for aircraft. In 1952, he received a bachelor's degree in physics and math from Hardin-Simmons University in Abilene, Tex. By 1954 he was working at Sandia, which was involved in making parts for nuclear weapons and at the time was overseen by the Atomic Energy Commission. Mr. Whitfield's duties soon included contamination control. By 1960, he had established his basic idea for the clean room. "I thought about dust particles," Mr. Whitfield told Time magazine in 1962. Where are these rascals generated? Where do they go? The clean room was patented through Sandia, and the government shared it freely among manufacturers, hospitals and other industries. Mr. Whitfield's original clean room was only about six feet high, built as a small, self-contained unit. Some modern electronic devices, including the iPhone, are now built in China in huge clean rooms in structures that are more than a million square feet. Workers wear protective clothing, and other anticontamination methods have been added, but they still depend on Mr. Whitfield's approach to suck up dust. "Relative to these electronics, the particles are just massive boulders that would short out all of your electronics and make them not work," Mr. Herrera said. The core technology, just the cleaning part, hasn't really changed a lot. Mrs. Whitfield said she was often been asked if her husband was a particularly fastidious man, and she always noted that he tended not to put his shoes away. He did live in a tidy house, though, and colleagues say he never tired of getting out a flashlight and shining it sideways across his coffee table to illuminate the prevalence of tiny dust particles that most people never notice.