Interfacial force sensor with force-feedback control

Conference · Mon Jan 01 00:00:00 EST 1990

OSTI ID:6226235

Joyce, S A; Houston, J E; Smith, B K

A new interfacial force microscope capable of measuring the forces between two surfaces over the entire range of surface separations, up to contact, has been developed. 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 balances the interfacial forces at the sensor, maintaining the common capacitor plate at its rest position. This control eliminates the instability which occurs with the conventional cantilever-based force sensors when the attractive force gradient exceeds the mechanical stiffness of the cantilever. The ability to measure interfacial forces at surface separations smaller than this instability point using the feedback control is demonstrated. 11 refs., 3 figs.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• Sponsoring Organization: DOE/DP
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6226235
• Report Number(s): SAND-90-2558C; CONF-901244-3; ON: DE91004897
• Resource Relation: Conference: 1990 international electron device conference, San Francisco, CA (USA), 10-12 Dec 1990
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
47 OTHER INSTRUMENTATION
SURFACE FORCES
MEASURING METHODS
CAPACITORS
CONTROL SYSTEMS
DESIGN
FEEDBACK
INTERFACES
MEASURING INSTRUMENTS
MICROSCOPES
PERFORMANCE TESTING
ELECTRICAL EQUIPMENT
EQUIPMENT
TESTING
656002* - Condensed Matter Physics- General Techniques in Condensed Matter- (1987-)
440800 - Miscellaneous Instrumentation- (1990-)