Francis Thomas Bacon was born at Ramsden Hall, Billericay, Essex on 21 December 1904. He was educated at Eton College, 1918-1922, specialising in science and winning the Moseley Physics Prize in 1922, and at Trinity College, Cambridge obtaining a third class in the Mechanical Sciences Tripos in 1925.

He served an apprenticeship at C.A. Parsons and Co. Ltd, Heaton Works, Newcastle upon Tyne, 1925-1928, subsequently working in the Searchlight Reflector and Research and Development Departments at Parsons, 1928-1940. It was while at Parsons in 1932 that he first came to appreciate the potential of the fuel cell and set himself the task of carrying out the practical engineering to prepare the way for it to be considered for commercial application. In 1940-1941 he started full-time work on the hydrogen-oxygen fuel cell at King's College London with the financial support of the consulting engineers Merz and McLellan. From 1941 to 1946 he was temporary experimental officer at H.M. Anti-Submarine Experimental Establishment, Fairlie, Ayrshire, working on ASDIC, the underwater submarine detection system. In 1946 he resumed experimental work on the hydrogen-oxygen fuel cell at Cambridge University, first in the Department of Colloid Science, then in the Department of Metallurgy and from 1951 to 1956 in the Department of Chemical Engineering. This work was supported financially by the Electrical Research Association. In 1956 Bacon became consultant to the National Research Development Corporation (NRDC) undertaking fuel cell development work at the Cambridge engineering firm Marshalls where a 6kW forty cell battery unit was demonstrated in August 1959. From 1962 to 1971 he was principal consultant on fuel cells to Energy Conversion Ltd, the first British effort to manufacture fuel cells, first at the BP Research Centre, Sunbury on Thames, Surrey and then at Basingstoke, Hampshire. From 1971 to 1973 he was consultant on fuel cells to Fuel Cells Ltd, at the Atomic Energy Research Establishment, Harwell, Oxfordshire. In 1973 he retired though he continued to follow the development of fuel cells very closely for the rest of his life.

Although Bacon hoped to see the adoption of a high efficiency/low pollution fuel cell in everyday applications such as transport, it was in the unforeseen application of space exploration that the Bacon cell achieved its most notable success in his lifetime. In the USA the Pratt and Whitney Division of United Aircraft took out a licence on the Bacon patents and used the concept of the Bacon cell in a successful bid to provide electrical power for the Apollo moonshot. The fuel cells operated successfully in the manned moon flights and subsequent space applications, providing electricity for the functioning of systems and the production of drinking water. Thus Bacon's pioneering work may be considered essential to the Apollo programme.

Bacon was appointed to the Order of the British Empire in 1967. He was elected FRS in 1973 and became an initial Fellow of the Fellowship of Engineering in 1976. Amongst other honours and awards of note are the National Aeronautics and Space Administration Award for Scientific and Technical Contribution in 1976, the Electrochemical Society's Vittorio de Nora - Diamond Shamrock Award in 1978, an honorary degree from the University of Newcastle upon Tyne in 1980 and the first Grove medal commemorating the work of Sir William Grove in 1991. He married Barbara Papillon in 1933 (one son, one daughter, and one son deceased). He died on 24 May 1992.