A new capacitive sensor for displacement measurement in a surface force apparatus

Frédéric Restagno (1) , Jérôme Crassous (1) , E. Charlaix (2) , M. Monchanin (2)

1 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
2 LPMCN - Laboratoire de Physique de la Matière Condensée et Nanostructures

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.

Domaines: Matière Molle [cond-mat.soft]

Frédéric Restagno, Jérôme Crassous, E. Charlaix, M. Monchanin. A new capacitive sensor for displacement measurement in a surface force apparatus. Measurement Science and Technology, 2001, 12, pp.16-22. ⟨10.1088/0957-0233/12/1/302⟩. ⟨hal-00122681⟩