Design super robots to save energy making rackets (12)
I believe the answer is:
obstreperous
'making rackets' is the definition.
(obstreperous means noisy or making a racket)
'design super robots to save energy' is the wordplay.
'design' indicates anagramming the letters.
'to save' indicates putting letters inside.
'energy' becomes 'e' (physics symbol as in E=mc2).
'super'+'robots'='superrobots'
'superrobots' is an anagram of 'obstreprous'.
'obstreprous' enclosing 'e' is 'OBSTREPEROUS'.
(Other definitions for obstreperous that I've seen before include "Bolshie" , "Noisily aggressive" , "Noisily defiant" , "Noisy, hard to control" , "Disruptive" .)