A new force sensor incorporating force‐feedback control for interfacial force microscopy

A new interfacial‐force microscope capable of measuring the forces between two surfaces over the entire range of surface separations, up to contact, is described. The design is centered around a differential‐capacitance displacement sensor where the common capacitor plate is supported by torsion bar...

Full description

Saved in:
Bibliographic Details
Published in:Review of scientific instruments 1991-03, Vol.62 (3), p.710-715
Main Authors: Joyce, Stephen A., Houston, J. E.
Format: Article
Language:English
Subjects:
440800 - Miscellaneous Instrumentation- (1990-)
DESIGN
ELECTRON MICROSCOPES
Exact sciences and technology
FEEDBACK
Instruments, apparatus, components and techniques common to several branches of physics and astronomy
INTERFACES
MEASURING METHODS
MICROSCOPES
OTHER INSTRUMENTATION
Other topics in instruments, apparatus, components and techniques common to several branches of physics and astronomy
Physics
SURFACE FORCES
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A new interfacial‐force microscope capable of measuring the forces between two surfaces over the entire range of surface separations, up to contact, is described. The design is centered around a differential‐capacitance displacement sensor where the common capacitor plate is supported by torsion bars. A force‐feedback control system is incorporated which balances the interfacial forces at the sensor, maintaining the common capacitor plate at its rest position. This control therefore eliminates the instability or ‘‘jumping’’ which occurs with conventional cantilever‐based force sensors when the attractive force gradient between the fixed sample and sensor exceeds the mechanical stiffness of the cantilever. The operating characteristics of the sensor and its ability to measure interfacial forces using the feedback control at surface separations smaller than this instability point are demonstrated.
ISSN:0034-6748
1089-7623
DOI:10.1063/1.1142072