Liu’s interest in particle measurement began when he worked to find ways to calibrate existing equipment and determine methods the particles not visible to the naked eye could be even more precisely measured. The most common instrument used in aerosol research is the particle spectrometer - a decades-old device used to measure the concentration of pollutants in the air.

His research on the extremely small particles in air and liquids has led to advances in measuring and controlling environmental contaminates.  This technology is important in many applications, including contamination control in microelectronics manufacturing and other clean room manufacturing, pharmaceutical and air pollution control industries, industrial hygiene, respiratory protection devices, and biotechnology and atmospheric sciences.  

The importance of his work is apparent in the manufacturing industries which require clean room technology.  For example, when dealing with microchips even the smallest particle of foreign material can contaminate the chip and cause it to be defective.  These silicone-based chips are extremely sensitive and particles not visible to the naked eye can cause irreparable damage.

In the weightlessness of space, dust as well as any crumbs just keep floating around. "Every time I opened up the (food) bag, the crumbs would come crowding out like a swarm of bees," said Scott Carpenter in 1962 after becoming the second American to orbit the Earth.

"There have been a number of reports by astronauts (on previous flights) saying it's fairly dusty - they can see the dust when sunlight comes in," Liu said.  "Some crews have complained of eye or throat irritation," added Dane Russo, environmental health systems project manger at the Johnson Space Center in Houston, Texas.  Russo said it's not clear whether dust triggered those problems, but there are enough suspicions to find out more.

How does dust get into a spaceship with all the "clean rooms" and other precautions already taken?  "People are kind of dusty," Liu said. Tiny particles flake off from the hair and skin, as well as from shoes and clothes, of the astronauts and the people who service the spacecraft. On Earth this settles down and is swept away. In space it just floats around.

So Liu's team, widely known for its earthly studies of air quality, was commissioned by NASA to design and build the 47 pounds of automated gear that flew on the Space Shuttle Columbia in 1990, inside a breadbox-size container.

The sophisticated air-filtration systems aboard the shuttle are designed primarily to keep dust from gumming up key electronic gear, Russo explained.  The Minnesota experiments will determine whether new equipment is needed for future spaceships that will concentrate on cleaning up the air that astronauts breathe.

Liu was a member of the University’s mechanical engineering faculty from 1960 to 2002, and in 1993 he was appointed a Regents' Professor, the highest distinction awarded to University faculty.  He directed the Particle Technology Laboratory in the Department of Mechanical Engineering from 1973 to 1997.  The Particle Technology Laboratory is dedicated to the study of minute particles and problems they can cause. 

Liu is a widely published University of Minnesota Regents Professor Emeritus* - the author or co-author of more than 400 publications, including four books.  He is also an inventor with more than 60  U.S. and foreign patents for breakthrough technologies in aerosol research and related fields.  His body of work has positioned the State of Minnesota as a leader in the field of aerosol instrumentation.

Liu retired from the University after four decades of exemplary teaching and research.  He founded and now serves as the President and CEO of MSP Corporation, an instrument and equipment company that designs, manufactures and markets products in the semiconductor, pharmaceutical and air pollution control industries; precision instruments that apply micro- and nano-particle technology to scientific research and industrial applications.    

MSP Corporation was incorporated in 1985 and is based in Shoreview, Minnesota.  The company has production distribution centers in Europe, Asia, the United States, Canada, and South America.

Liu, was born in 1934 and raised in Nebraska.  He earned a bachelor of science degree in mechanical engineering from the University of Nebraska in 1956 and a doctorate decree in mechanical engineering from the University of Minnesota in 1960.

Professor Lui is one of the four founding fathers of the American Association of Aerosol Research.  Founded in 1982, the AAAR fosters scientific and technical advancements related to air pollution, industrial hygiene, atmospheric sciences, clean room technology and nuclear safety.  Members include professionals and students from academia, government, and industry throughout the world.

Professor Liu is also a founding father of the AAAR journal, Aerosol Science and Technology, and he helped establish the International Aerosol Research Assembly.

The AAAR has established the Benjamin Y. H. Liu Award to recognize outstanding contributions to aerosol instrumentation and experimental techniques that have significantly advanced the science and technology of aerosols.  The award honors Professor  Liu for his leadership in the aerosol community and his contributions to aerosol science through instrumentation and experimental research.

* A professor emeritus is one who is retired but retains an honorary title corresponding to that held immediately before retirement.

Note:  This short biography has been compiled from information in the nomination form submitted to the Minnesota Inventors Hall of Fame, from an article published in the StarTribune newspaper on January 8, 1990, and from information available on the Internet.