by his son, Hugh De Pree, who served as CEO until the mid-1980s. Hugh De Pree was succeeded by his brother Max De Pree, who held the position until 1990. In 1961, Herman Miller set up the Herman Miller Research Division, based in Ann Arbor, Michigan. This division developed the "Action Office" line in 1964 under the supervision of Robert Propst and with the design assistance of George Nelson's New York design studio. Though the initial line, known as "Action Office I", was not a success, it led Propst to develop the "Action Office II" line, which introduced the office cubicle. In 1978, Action Office II was renamed simply "Action Office". Herman Miller's line of Action Office products generated sales of over $5 billion . George Nelson's influence at Herman Miller gradually declined during the 1970s as new designers joined the company, including Don Chadwick and Bill Stumpf, who in the 1990s developed the highly-successful Aeron chair. In 1981, Herman Miller started to work with the Italian designer Clino T. Castelli on the process of designing physical environments, a so-called Design Primario. Designer Tom Newhouse introduced the "Newhouse Group" of free-standing furniture in 1987, and assisted with the "Ethospace" wall panel system for the Action Office line. Ray Wilkes designed the "Modular Seating Group", popularly known as the Chicklet Chairs. In 2010, the firm acquired Colebrook Bosson Saunders, a designer and manufacturer of ergonomic furniture. The acquisition of Knoll by Herman Miller was announced in April 2021 in a $1.8 billion deal. The acquisition closed July 19, 2021. In July 2021, the company rebranded as MillerKnoll. Brands In addition to Herman Miller and Knoll, the company owns notable brands including Design Within Reach, Colebrook Bosson Saunders, Dates Weiser, Edelman Leather, Holly Hunt, Hay, Maharam, and Muuto. Workplace According to CNN Money, , Herman Miller was ranked as the second most admired company in the Home Equipment, Furnishing division. In March 2008, Herman Miller settled an antitrust lawsuit with the states of New York, Michigan, and Illinois for $750,000. The lawsuit focused on Herman Miller's use of a suggested retail pricing policy. Sustainability Herman Miller has engaged in a number of initiatives to promote sustainability. The company has developed a technique of mixing sawdust with chicken manure to produce topsoil. Management of the company has expressed concerns about global warming, and the company was using 27% renewable energy . Herman Miller