  In force sensing experiments intended to measure non-Newtonian gravitational
signals electrostatic patch potentials can give rise to spurious forces,
torques, and noise. Undesired patch-induced interactions can lead to systematic
effects which limit accuracy, and noise can place lower limits on precision. In
this paper we develop the theory for electrostatic patch effects on
isoelectronic experiments, where their mean effect is nullified by design. We
derive analytical expressions for the patch force and torque power spectrum to
estimate the limitations introduced by patch-induced signals.
