Molecular Imaging Corporation

Arizona Board of Regents, a Body Corporate

Molecular Imaging Corporation Arizona Board of Regents

Wenhai Han

Stuart Lindsay

Tianwei Jing

Steven K Harbaugh

A scanning probe microscope for generating a signal corresponding to the surface characteristics of a scanned sample is provided and includes a force sensing probe tip disposed on a first side of a free end of a flexible cantilever which is adapted to be brought into close proximity to a sample surface; a magnetized material disposed on a second side opposite the first side of the flexible cantilever; an XY scanner for generating relative scanning movement between the force sensing probe tip and the sample surface; a Z control for adjusting the distance between the force sensing probe tip and the sample surface; and a deflection detector for generating a deflection signal indicative of deflection of the flexible cantilever. The scanning probe microscope also includes an ac signal source and a magnetic field generator for generating a magnetic field, with the magnetic field generator being coupled to the ac signal source so as to modulate the magnetic field with the ac signal. The force-sensing cantilever is magnetized with a moment along the soft axis of the cantilever.

Magnetic modulation of force sensor for AC detection in an atomic force

An atomic force microscope and method of operation are provided and include a force sensing probe tip adapted to be brought into close proximity with a sample surface, a scanning element for generating relative movement between the probe tip and the sample surface, a device for generating a magnetic field to cause deflection of the probe tip, a driver for the device, the driver including a source of alternating current and a source of a second current of a controlled magnitude, and a detector for detecting the position of the probe tip. In a preferred mode of operation, two signals, one of alternating current and the other of a fixed, but variable, current, are applied to cause a displacement of the time-average position of the probe tip.

Microscope for compliance measurement

A force sensing cantilever for use in a scanning probe microscope has both a top side and a bottom side. From the bottom side extends a probe tip. The bottom side is coated with a thin film of a first material and the top side is coated with a thin film of a second material. The first and second materials may be the same or they may be different. The materials and thicknesses of the respective films are selected so as to create opposing forces to counter the tendency of such cantilevers to bend when a thin film is applied to only one side thereof.

Cantilevers for a magnetically driven atomic force microscope

In accordance with a first aspect of the present invention, the sensitivity of a magnetically modulated AC-AFM is substantially improved by the use of a ferrite-core solenoid for modulating the magnetic cantilever of the ACAFM. In accordance with a second aspect of the present invention, the detection system for a magnetically modulated AC-AFM incorporates AC coupling of the signal from the position sensitive detector/beam deflection detector in order to remove the DC component of the signal, resulting in significantly improved dynamic range over systems utilizing DC coupling. High frequency modulation signals are detected through the use of fast analog multipliers which, after active filtering, give a low frequency signal which may be processed by digital electronics. In accordance with a third aspect of the present invention, operation of the microscope at small amplitudes of oscillation leaves small asperities on the tip intact and results in dramatic improvement in resolution.

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Tempe, AZ, United States of America

Wenhai Han