  Using first-principles density functional theory, we study piezoelectricity
in short-period superlattices made with combination of ferroelectric and
paraelectric components and exhibiting polar discontinuities. We show that
piezoelectric response of such a superlattice can be tuned both in terms of
sign and magnitude with a choice of its components. As these superlattices with
nonswitchable polarization do not undergo ferroelectric transitions, we predict
them to exhibit a robust piezoelectric response with weaker temperature
dependence compared to their bulk counterparts.
