We present a new capacitive sensor for displacement measurement in a Surface Forces Apparatus (SFA) which allows dynamical measurements in the range of 0-100 Hz. This sensor measures the relative displacement between two macroscopic opaque surfaces over periods of time ranging from milliseconds to in principle an indefinite period, at a very low price and down to atomic resolution. It consists of a plane capacitor, a high frequency oscillator, and a high sensitivity frequency to voltage conversion. We use this sensor to study the nanorheological properties of dodecane confined between glass surfaces.
@article{arxiv.cond-mat/0102225,
title = {A new capacitive sensor for displacement measurement in a surface force apparatus},
author = {F. Restagno and J. Crassous and E. Charlaix and M. Monchanin},
journal= {arXiv preprint arXiv:cond-mat/0102225},
year = {2009}
}