Scanned probe microscopy techniques can be used to create nanometerresolution surface maps of forces as small as an attonewton. In this work, a new method for measuring local electric field gradients at the surface of a polymer film is presented. The centerpiece of this thesis is a protocol for measuring and deciphering noise in a cantilever's resonance frequency (Chapter 4). The protocol was tested on thin polymer film samples; these measurements confirmed the predictions of a zero-free parameter theory described in Chapter 3, which relates cantilever frequency noise to local dielectric fluctuations emanating from within the polymer. Chapter 5 is a presentation of preliminary efforts towards achieving a local measurement of carrier mobility in an organic semiconductor.