US 4,935,634 AGranted

Atomic force microscope with optional replaceable fluid cell

AssigneeThe Regents of the University of California

InventorsPaul K. Hansma, Barney Drake

Life of this patent

Estimating the term…

Loading patent…

Abstract

An atomic force microscope which is readily useable for researchers for its intended use without extensive lost time for setup and repair. The probe used therein is a cantilevered optical lever which imparts surface information in a gentle and reliable manner by reflecting an incident laser beam. The probe is carried by a replaceable probe-carrying module which is factory set up and merely inserted and fine tuned by the user. The probe-carrying module also includes the provision for forming a fluid cell around the probe. Fluid can be inserted into and/or be circulated through the fluid cell through incorporated tubes in the porbe-carrying module. Electrodes are also provided in the fluid cell for various uses including real-time studies of electro-chemical operations taking place in the fluid cell. The piezoelectric scan tube employed includes a voltage shield to prevent scanning voltages to the tube from affecting data readings. Samples are easily mounted, replaced, and horizontally adjusted using a sample stage which is magnetically attached to the top of the scan tube. Calibration tools are provided to make initial set up and fine tuning of the microscope a simple and straightforward operation requiring little or no technical talent.

Claims58

Dependent claims

An atomic force microscope which is quickly and easily set up and in which the probe thereof is easily replaceable and resists breakage during setup comprising:

(a) a horizontal base member;
(b) a scan tube vertically supported at a bottom end by said base member and having a top surface for holding a sample to be scanned and moveable in x-, y-, and z-directions as a result of scanning voltages applied thereto;
(c) first support means extending upward from said base member;
(d) a sample holding block having a chamber therein, said sample holding block having a first bore communicating with said chamber through a bottom surface, a second bore communicating with said chamber through a top surface, and a third bore communicating with said chamber at an acute angle to said second bore, said sample holding block being positioned with said scan tube passing through said first bore and supported by said first support means;
(e) second support means extending upward from said bottom surface into said chamber;
(f) a probe-carrying module having top and bottom surfaces removably disposed in said chamber and supported by said second support means, said bottom surface having a probe attached thereto and extending downward therefrom at an acute angle with respect to said bottom surface of said probe-carrying module and with a tip of said probe positioned to contact a sample mounted on said top surface of said scan tube;
(g) a source of a laser beam mounted for directing said laser beam down said second bore from said top surface of said sample holding block to pass through said probe-carrying module, strike said probe, and be reflected back through said probe-carrying module and down said third bore to an outer end thereof;
and,
(h) photoelectric sensor means having an active surface positioned over said outer end of said third bore for developing an electrical signal at an output thereof reflecting the position on said active surface at which said laser beam strikes said active surface.

6 more elements

An atomic force microscope having extended use capabilities comprising:

(a) a horizontal base member;
(b) a scan tube vertically supported at a bottom end by said base member and having a top surface for holding a sample to be scanned and moveable in x-, y-, and z-directions as a result of scanning voltages applied thereto;
(c) first support means extending upward from said base member;
(d) a sample holding block having a chamber therein, said sample holding block having a first bore communicating with said chamber through a bottom surface, a second bore communicating with said chamber through a top surface, and a third bore communicating with said chamber at an acute angle to said second bore, said sample holding block being positioned with said scan tube passing through said first bore and supported by said first support means;
(e) second support means extending upward from said bottom surface into said chamber;
(f) a probe-carrying module having a probe attached thereto and extending downward therefrom at an acute angle with a tip of said probe positioned to contact a sample mounted on said top surface of said scan tube, said probe carried by said probe-carrying module comprising a substrate attached to said probe-carrying module and an arm of a smooth-surfaced, minimally self-biased material cantilevered outward from a bottom front edge of said substrate to form an optical lever, said arm having a probe point at an outer end thereof;
(g) a source of a laser beam mounted for directing said laser beam down said second bore from said top surface of said sample holding block to strike said probe and be reflected down said third bore to an outer end thereof;
and,
(h) photoelectric sensor means having an active surface positioned over said outer end of said third bore for developing an electrical signal at an output thereof reflecting the position on said active surface at which said laser beam strikes said active surface.

6 more elements

An atomic force microscope containing an easily replaceable probe-carrying member including an optional fluid cell comprising:

(a) a horizontal base member;
(b) a scan tube vertically supported at a bottom end by said base member and having a top surface for holding a sample to be scanned and moveable in x-, y-, and z-directions as a result of scanning voltages applied thereto;
(c) first support means extending upward from said base member;
(d) a sample holding block having a chamber therein, said sample holding block having a first bore communicating with said chamber through a bottom surface, a second bore communicating with said chamber through a top surface, and a third bore communicating with said chamber at an acute angle to said second bore, said sample holding block being positioned with said scan tube passing through said first bore and supported by said first support means;
(e) second support means extending upward from said bottom surface into said chamber;
(f) a probe-carrying module of an optically transparent material having top and bottom surfaces removably disposed in said chamber and supported by said second support means, said bottom surface having a probe attached thereto and extending downward therefrom at an acute angle with respect to said bottom surface of said probe-carrying module and with a tip of said probe positioned to contact a sample mounted on said top surface of said scan tube, said probe-carrying module including an angled pad on said bottom surface thereof and said probe carried by said probe-carrying module comprising,
(f1) a substrate attached to said pad, and
(f2) an arm of a smooth-surfaced, minimally self-biased material cantilevered outward from a bottom front edge of said substrate to form an optical lever, said arm having a probe point at an outer end thereof;
(g) sealing means surrounding said probe and attached to said bottom surface of said probe-carrying module for sealing to a top surface of a sample to form a fluid cell around said probe;
(h) a source of a laser beam mounted for directing said laser beam down said second bore from said top surface of said sample holding block to pass through said probe-carrying module, strike said probe, and be reflected back through said probe-carrying module and down said third bore to an outer end thereof;
and,
(i) photoelectric sensor means having an active surface positioned over said outer end of said third bore for developing an electrical signal at an output thereof reflecting the position of said active surface at which said laser beam strikes said active surface.

9 more elements

Dependencies are inferred from the claim text.