Groovy isn't it? The plastic – or more accurately glass reinforced polyester – chair in the shape of a tooth looks every inch the product of the 1960s. Called the Molar Chair, its designer Wendell Castle was known as the father of American art furniture and the chair was just one piece he designed in his 60-plus year career. He died last month age 85.

The Kansas-born designer's skill was his ability to work so playfully and dramatically in the intersection between sculpture and design. It's a route many designers have followed. He worked in plastics – mostly brightly coloured in the 1960s and 1970s – although it is his work in wood, sinuous shaped chairs, tables with prancing anthropomorphic legs, that will probably prove most enduring as examples of his art furniture. His New York Times obituary called him a "whimsical designer who coaxed wood into weird, mind-bending shapes". His most quoted line, "Wood, I realised, could be shaped and formed and carved in ways limited only by my imagination," gives an insight into his creative approach. His highly collectible work is in many international museum collections including the V&A, Moma, the Museum of Fine Art in Boston and the Smithsonian.