Manhattan Project badge, ca. 1945.
The Army designed a patch for their staff at the Manhattan Project in Los Alamos New Mexico, a rather childishly-rendered but scary image of a brain (with Army star) splitting an atom; typical Army graphic design for badges is usually quite good; they must have been in a hurry on this one.
This description of the patch is from Associated Press:
"WASHINGTON, Aug. 24, 1945-(AP)- A special shoulder patch will be given to approximately 3500 Army officers and enlisted men who were assigned to the Manhattan Engineer District, the secret organization that produced the atomic bomb.
The War Department, announcing this today, said the triangular patch has a blue field representing the universe, a small Army Service Force Star signifying command and a question mark in white surrounding the ASF Star to indicate secrecy cloaking the Manhattan Engineer District. The tail of the question mark becomes a lightning stroke, hitting and splitting an atom."
It was later used as-is by the AFSWP, a combined-armed-forces repository for atomic weapons technology that existed from 1948 through 1959, when it mutated into the Defense Atomic Support Agency, and in 1971 became the present-day Defense Nuclear Agency.