Alvin M. Marks, a prolific inventor who held patents on polarized film for sunglasses and a 3-D moviemaking process, among other things, died May 25 in Gardner, Mass. He was 97. The cause was liver and pancreatic cancer, said Molly Bennett Aitken, his former wife.

A man capable of pragmatism and imagination, Marks held 122 patents. An expert in optics, he developed several variants of polarized film used in sunglasses and to reduce glare on television screens; a headlight system to aid night driving; and window panels that change from transparent to opaque and back again.

For much of the latter half of his career, Marks focused on developing alternative and low-cost energy sources. He served as an adviser to President John F. Kennedy and in 1967 was a consultant to the U.S. Senate on new technologies.

His inventions in the energy field include several aerosol electric power generators for home use as well as larger-scale generators. In recent years, he had been developing an array of minute antennas capable of collecting sunlight and transforming it into electricity, as well as a corresponding battery for storing it.

Born in Brooklyn on Oct. 28, 1910, he got his degree in electrical engineering from Cooper Union. Because he could read German, his former wife said, he spent much of his Navy service during World War II translating Nazi documents.

After his first two marriages ended in divorce, he married Molly Bennett in 1967; they divorced a decade later, and she subsequently married Gerard Aitken III, who became Marks' business partner. Aitken died in 1987, and Marks adopted the two young children his partner and friend had had with his former wife.

In 1989, Marks won a patent with Peter G. Diamandis for perhaps his most audacious invention, a plan to circumvent conventional space travel with a 6.6-million-pound, 180-foot train that would be propelled into outer space. It would cost trillions, but would cut the cost of space exploration drastically.

NEW YORK TIMES