Cemil Bagci was a professor of Mechanical Engineering at the University of Tennessee until 1996.
There's no firm evidence to suggest that Bagci was the designer of R2-D2, in fact Ralph McQuarrie is credited as being the cover artist for the first confirmed sighting of R2-D2 (complete with waving arms) on the cover of The Adventures of the Starkiller: Episode 1;
There are also some some (unfortunately undated) McQuarrie concept sketches that supposedly pre-date the book cover;
When asked in a brief interview for his university website (dated January 01/31/97) whether his name was commemorated in the film, he confirmed that this was the case but stated (modestly, it seems) that his contribution had been minor.
Bagci's contribution is commemorated in the movie with "Batchi" -- the
language spoken by household computers and home robots. "Tell your
uncle if he gets a translator to make sure it speaks Batchi" Luke
Skywalker's aunt calls out in an early scene as Luke and his uncle
head out to bargain with diminutive Jawas over their collection of
junked robots. One of the rejects did speak the language, and so C3P0
and his companion R2D2 begin their adventure in the film.
"The connection hasn't escaped Tennessee Tech students. "A student
came into my office just yesterday," Bagci said on Friday. "He said he
wanted to ask a question and it wasn't about coursework, it was about
'Star Wars.'" It was also little surprise. In the 20 years since 'Star
Wars' debuted, Bagci says doctors, acquaintances and even strangers
have commented on his name and asked if there was a connection to the
acclaimed science fiction trilogy. The fact that Bagci speaks
rapid-fire Turkish-accented English underscores the connection,
students wryly note."
Given that he didn't die until 1998, we could reasonably assume that he would have requested a correction if this press-release had made false assumptions.
There's also an interesting article on the Official Star Wars website relating to the problems that John Stears, Mechanical Effects Supervisor for Star Wars had encountered;
In 1976 when Stears approached animatronics experts for help in
creating the droids of Star Wars, he was told that it would be
'virtually impossible' to create mechanical beings with the
functionality he described, even for a film, without many years of
work. Stears gave up on the experts, and his crew had the robots ready
in a few months. Admittedly, there were many difficulties with the
experimental original working droids, especially in Tunisia, where
their radio-controls often went haywire, but in the end the creations
of Stears and his crew became a truly convincing set of cinema droids,
and R2-D2 was the standout.
Given that following the "consultation" the decision was taken to have a human actor inside R2-D2, it does beg the question whether the 'experts', presumably including Bagci were in fact correct that a fully animatronic R2-D2 would have been impossible.
On a side note, it's also worth noting that the word "Bocce" isn't found in any of the Star Wars screenplays or scripts until August 1, 1975 at the same time as the technical description of the "'droids" is greatly expanded, lending greater credence to the suggestion that the name was included after a technical consultation had taken place.