Born in Saint Petersburg to a working-class family, Demidov showed technical and engineering gifts at an early age.
In the winter of 1938, as a part of so-called UPTI Affair, he was arrested in Kharkiv, where he was working at the Kharkov Electrotechnical Institute as an experimentation physicist, after being served a summons for an internal passport check.
In July 1988, due to the order of Alexander Nikolaevich Yakovlev, a secretary in the Central Committee of the Communist Party of the Soviet Union, the seized documents were returned to his daughter.
116–145) – "People Die for Metal" ("Люди гибнут за металл") – a title drawn from a statement of Mephistopheles in 'Faust' by 'Goethe' – and "The Artist Baccilla and his Wonders" ("Художник Бацилла и его шедевр").
In 2008, on the centenary of his birth, his stories, collected by his daughter, were published in book form as "Чудная планета" (Miraculous Planet) (ISBN 9785715702197) by Возвращение press.