Heat engines for dilatonic Born–Infeld black holes

In the context of dilaton coupled Einstein gravity with a negative cosmological constant and a Born–Infeld field, we study heat engines where a charged black hole is the working substance. Using the existence of a notion of thermodynamic mass and volume (which depend on the dilaton coupling), the mechanical work takes place via the pdV terms present in the first law of extended gravitational thermodynamics. The efficiency is analyzed as a function of dilaton and Born–Infeld couplings, and the results are compared with analogous computations in the related conformal solutions in the Brans–Dicke–Born–Infeld theory and black holes in anti-de Sitter space-time.