  The environment-dependent dilaton field is a well-motivated candidate for
dark energy and naturally arises in the strong coupling limit of string theory.
In this article, we present the very first experimental constraints on the
parameters of this model. For this, we employ data obtained from the qBounce
collaboration and the Lunar Laser Ranging (LLR) experiment. Furthermore, we
forecast expected exclusion plots for the Casimir And Non Newtonian force
EXperiment (Cannex) soon to be realised in an improved setup. Finally, we
provide a detailed analysis of the screening mechanism and additional
symmetries of the dilaton field theory.
