Abstract:
A cleaning station for thoroughly cleaning the AFM component surfaces that are exposed to fluid during imaging of a sample supported in a fluid medium is disclosed. The cleaning station is designed to selectively expose the AFM component surfaces to cleansing agents, such as soap/detergent and water, plasma cleaning, etc., and cleaning tools, such as brushes, while protecting fluid sensitive components from exposure to the cleansing agents. The preferred embodiments are particularly beneficial for scanners in which the fluid sensitive components (actuator, sensor, connector, etc.) are integrated in the same device to which the cantilever holder is attached.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application seeks priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/480,984, filed on Apr. 29, 2011, the entirety of which is expressly incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to scanning probe microscopy in fluid, and more particularly, to an apparatus for cleaning the fluid exposed surface of a scanning probe microscope while protecting fluid sensitive components. 
     2. Description of Related Art 
     Scanning probe microscopes (SPMs), such as the atomic force microscope (AFM), are devices which typically employ a probe having a tip and which cause the tip to interact with the surface of a sample with low forces to characterize the surface down to atomic dimensions. Generally, the probe is introduced to a surface of a sample to detect changes in the characteristics of a sample. By providing relative scanning movement between the tip and the sample, surface characteristic data can be acquired over a particular region of the sample, and a corresponding map of the sample can be generated. 
     A typical AFM system is shown schematically in  FIG. 1 . An AFM  2  employs a probe device  3  including a probe  3  having a cantilever  4 . A scanner  5  generates relative motion between the probe  3  and a sample  6  while the probe-sample interaction is measured. In this way, images or other measurements of the sample can be obtained. Scanner  5  is typically comprised of one or more actuators that usually generate motion in three mutually orthogonal directions (XYZ). Often, scanner  5  is a single integrated unit that includes one or more actuators to move either the sample or the probe in all three axes, for example, a piezoelectric tube actuator. Alternatively, the scanner may be a conceptual or physical combination of multiple separate actuators. Some AFMs separate the scanner into multiple components, for example an XY actuator that moves the sample and a separate Z-actuator that moves the probe. The instrument is thus capable of creating relative motion between the probe and the sample while measuring the topography or some other property of the sample as described, e.g., in Hansma et al. U.S. Pat. No. RE 34,489; Elings et al. U.S. Pat. No. 5,266,801; and Dings et al. U.S. Pat. No. 5,412,980. 
     Notably, scanner  5  often comprises a piezoelectric stack (often referred to herein as a “piezo stack”) or piezoelectric tube that is used to generate relative motion between the measuring probe and the sample surface. A piezo stack is a device that moves in one or more directions based on voltages applied to electrodes disposed on the stack. Piezo stacks are often used in combination with mechanical flexures that serve to guide, constrain, and/or amplify the motion of the piezo stacks. Additionally, flexures are used to increase the stiffness of actuator in one or more axis, as described in U.S. Ser. No. 11/687,304, filed Mar. 16, 2007, entitled “Fast-Scanning SPM Scanner and Method of Operating Same.” Actuators may be coupled to the probe, the sample, or both. Most typically, an actuator assembly is provided in the form of an XY-actuator that drives the probe or sample in a horizontal, or XY-plane and a Z-actuator that moves the probe or sample in a vertical or Z-direction. 
     In a common configuration, probe  3  is often coupled to an oscillating actuator or drive  16  that is used to drive probe  3  to oscillate at or near a resonant frequency of cantilever  4 . Alternative arrangements measure the deflection, torsion, or other characteristic of cantilever  4 . Probe  3  is often a microfabricated cantilever with an integrated tip  7 . 
     Commonly, an electronic signal is applied from an AC signal source  18  under control of an SPM controller  9  to cause actuator  8  (or alternatively scanner  5 ) to drive the probe  3  to oscillate. The probe-sample interaction is typically controlled via feedback by controller  9 . Notably, the actuator  8  may be coupled to the scanner  5  and probe  3  but may be formed integrally with the cantilever  4  of probe  3  as part of a self-actuated cantilever/probe. 
     Often, a selected probe  3  is oscillated and brought into contact with sample  6  as sample characteristics are monitored by detecting changes in one or more characteristics of the oscillation of probe  3 , as described above. In this regard, a deflection detection apparatus  25  is typically employed to direct a beam towards the backside of probe  3 , the beam then being reflected towards a detector  11 , such as a four quadrant photodetector. The deflection detector is often an optical lever system such as described in Hansma et al. U.S. Pat. No. RE 34,489, but may be some other deflection detector such as strain gauges, capacitance sensors, etc. The sensing light source of apparatus  10  is typically a laser, often a visible or infrared laser diode. The sensing light beam can also be generated by other light sources, for example a He—Ne or other laser source, a superluminescent diode (SLD), an LED, an optical fiber, or any other light source that can be focused to a small spot. As the beam translates across detector  11 , appropriate signals are processed by a signal processing block  13  (e.g., to determine the RMS deflection of probe  3 ). The interaction signal (e.g., deflection) is then transmitted to controller  9 , which processes the signals to determine changes in the oscillation of probe  3 . In general, controller  9  determines an error at Block  14 , then generates control signals (e.g., using a PI gain control Block  32 ) to maintain a relatively constant interaction between the tip and sample (or deflection of the lever  4 ), typically to maintain a setpoint characteristic of the oscillation of probe  3 . The control signals are typically amplified by a high voltage amplifier  16  prior to, for example, driving scanner  5 . For example, controller  9  is often used to maintain the oscillation amplitude at a setpoint value, A S , to insure a generally constant force between the tip and sample. Alternatively, a setpoint phase or frequency may be used. Controller  9  is also referred to generally as feedback where the control effort is to maintain a constant target value defined by setpoint. 
     A workstation  17  is also provided, in the controller  9  and/or in a separate controller or system of connected or stand-alone controllers, that receives the collected data from the controller and manipulates the data obtained during scanning to perform data manipulation operating such as point selection, curve fitting, and distance determining operations. The workstation can store the resulting information in memory, use it for additional calculations, and/or display it on a suitable monitor, and/or transmit it to another computer or device by wire or wirelessly. The memory may comprise any computer readable data storage medium, examples including but not limited to a computer RAM, hard disk, network storage, a flash drive, or a CD ROM. 
     AFMs may be designed to operate in a variety of modes, including contact mode and oscillating mode. Operation is accomplished by moving the sample and/or the probe assembly up and down relatively perpendicular to the surface of the sample in response to a deflection of the cantilever of the probe assembly as it is scanned across the surface. Scanning typically occurs in an “x-y” plane that is at least generally parallel to the surface of the sample, and the vertical movement occurs in the “z” direction that is perpendicular to the x-y plane. Note that many samples have roughness, curvature and tilt that deviate from a flat plane, hence the use of the term “generally parallel.” In this way, the data associated with this vertical motion can be stored and then used to construct an image of the sample surface corresponding to the sample characteristic being measured, e.g., surface topography. In one practical mode of AFM operation, known as TappingModem™ AFM (TappingModem™ is a trademark of the present assignee), the tip is oscillated at or near a resonant frequency of the associated cantilever of the probe, or harmonic thereof. A feedback loop attempts to keep the amplitude of this oscillation constant to minimize the “tracking force,” i.e., the force resulting from tip/sample interaction, typically by controlling tip-sample separation. Alternative feedback arrangements keep the phase or oscillation frequency constant. As in contact mode, these feedback signals are then collected, stored and used as data to characterize the sample. 
     Regardless of their mode of operation, AFMs can obtain resolution down to the atomic level on a wide variety of insulating or conductive surfaces in air, liquid or vacuum by using piezoelectric scanners, optical lever deflection detectors, and very small cantilevers fabricated using photolithographic techniques. Because of their resolution and versatility, AFMs are important measurement devices in many diverse fields ranging from semiconductor manufacturing to biological research. Note that “SPM” and the acronyms for the specific types of SPMs, may be used herein to refer to either the microscope apparatus or the associated technique, e.g., “atomic force microscopy.” 
     One particular use of AFMs is the imaging of samples in a fluid/liquid medium. For example, a TappingMode™ AFM may be used for the visualization of supported lipid bilayers or adsorbed single polymer molecules under liquid medium. For the imaging of samples supported in a fluid medium, some AFM components will reside in the fluid or liquid medium. To maintain the integrity of the sample, i.e., preventing contamination of the sample, the exposed surface of those components must be substantially free of any contaminants. Accordingly, before imaging, or otherwise capturing data, of a sample supported in the fluid medium, the exposed surfaces must be cleaned. In the most general terms, cleaning the exposed surfaces, for instance, the scanner, involves exposing the surfaces to one or more cleaning agents, i.e., soap and/or detergent, as well as a scrubbing tool, i.e., brush. One of the challenges with cleaning the surfaces that are loaded into the fluid medium is ensuring that fluid sensitive components are not exposed to the cleaning fluids. Hence, conventional AFMs have the fluid sensitive components, e.g., actuator elements and sensor elements, encased in a sealed housing that is separate from the cantilever holder, which is exposed to the fluidic sample and therefore should be cleaned prior to sampling. Having the cantilever holder separable from the sealed housing requires a mounting interface, which adds to the mass of the scanner and reduces the stiffness of the scanner. 
     As described in U.S. Ser. No. 11/687,304 high resolution at higher scan rates is achievable by increasing the fundamental resonant frequency of the tip scanner. Two of the numerous ways in which the fundamental resonant frequency of a tip scanner can be increased is scanner mass and scanner stiffness. More particularly, decreasing the mass of the scanner increases the fundamental resonant frequency of the tip scanner. Similarly, flexures, for example, can increase the stiffness of the scanner and consequently increase the scanner&#39;s fundamental resonant frequency. Thus, while a cantilever holder separable from the “fluid proof” encasing for the fluid sensitive components eases the challenges associated with cleansing the cantilever holder and the exposed surface(s) of the scanner; ultimately, such a construction decreases the fundamental resonant frequency of the scanner and therefore reduces the scan rate for the scanner. On the other hand, integrating the cantilever holder with the housing for the scanner electronics risks exposure of the fluid sensitive components to the cleaning agents during cleaning of the scanner. 
     One proposed solution is to enclose the scanner electronics, e.g., piezo actuators and strain gauges, in a housing to which the cantilever holder is attached. This integration of the electrical components and the cantilever holder provides a less massive and more stiff scanner, as described in U.S. Ser. No. 13/068,052 the disclosure of which is incorporated herein. To protect the electrical components from exposure to the cleaning agents and/or solutions, the components could be encased in an elastic sealant. However, given the highly sensitive nature of AFMs, the elastic sealant may negatively affect performance. Additionally, it is possible that the sealant could degrade over time as it is exposed to the cleaning agents and/or solutions. An improved solution was desired. 
     SUMMARY OF THE INVENTION 
     The present invention provides a cleaning station for thoroughly cleaning the AFM component surfaces that are exposed to fluid during sampling of a sample supported in a fluid medium. The cleaning station is designed to selectively expose the AFM component surfaces to cleansing agents, such as soap/detergent and water, plasma cleaning, etc., and cleaning tools, such as brushes, while protecting fluid sensitive components from exposure to the cleansing agents. The invention is particularly beneficial for scanners in which the fluid sensitive components (actuator, sensor, connector, etc.) are integrated in the same device to which the cantilever holder is attached, as described in U.S. Ser. No. 13/068,052 and generally shown at  FIGS. 15-17 . 
     The cleaning station is designed to temporarily enclose the fluid sensitive components of the scanner yet expose the surfaces of the scanner that contact the sampled fluid during imaging. In this regard, the surfaces that require cleaning are exposed to the environment for washing/cleaning while the fluid sensitive components are enclosed in such a way that they are not exposed to the environment during the cleaning process. In one form of the cleaning station, the scanner to be cleaned is seated in an opening formed in fluid sealed housing. The fluid sealed housing effectively provides a temporary enclosure for the fluid sensitive components of the scanner. An opening is formed in the fluid sealed housing such that when the scanner is loaded into the fluid sealed housing, the surface of the scanner to be cleaned is exposed. A gasket in the opening engages the outer wall of the scanner and is operative to provide a watertight seal against the outer wall(s) of the scanner. Hence, cleansing agents applied to the exposed surface of the scanner are prevented from flowing into the temporary enclosure. As such, cleaning agents such as soap and/or detergents, water and pressurized gasses may be applied to the surface of the scanner to be cleaned without those materials leeching into the internal chamber of the fluid sealed enclosure. 
     The cleaning station may also be sized to enclose the cable that is connected to the electronics of the scanner. As the exposed end of the cable may also be sensitive to the cleaning agents, enclosing the exposed end of the cable within the fluid sealed housing prevents exposure of the exposed end of the cable to the cleaning agents during cleaning of the exposed surface of the scanner. Alternately, the exposed end of the cable may be secured in a separate fluid sealed housing to prevent exposure to the cleaning agents. 
     The cleaning station is preferably made from corrosion-resistant components that can withstand repeated exposure to otherwise caustic cleansing agents and fluids. Additionally, the cleaning station has mechanical integrity sufficient to withstand exposure to high pressure cleaning fluid such as pressurized gases or plasma. 
     The cleaning station may be configured to hold a single scanner for cleaning or may be configured to hold multiple scanners to allow simultaneous cleaning of the multiple scanners. To accommodate more than one scanner, the fluid sealed housing may have multiple openings into which multiple scanners may be seated. Each opening has a gasket to seal the sensitive electrical components of each scanner from the cleaning agents. 
     According to a preferred embodiment, an apparatus for cleaning a surface of an AFM component includes a housing defining an enclosure. An opening formed in the housing and into the enclosure is also provided. A seal supported in the opening and configured to engage an outer surface of the AFM component loaded into the opening operates to prevent the ingress of cleaning fluid presented to an exposed surface of the AFM component into the enclosure. 
     These and other features and advantages of the invention will become apparent to those skilled in the art from the following detailed description and the accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a schematic block drawing of a Prior Art atomic force microscope (AFM); 
         FIG. 2  is an isometric view of a cleaning station for cleaning an AFM scanner according to one embodiment of the invention; 
         FIG. 3  is a partial cutaway view of the cleaning station of  FIG. 2 ; 
         FIG. 4  is an enlarge view of the cleaning station of  FIG. 3 ; 
         FIG. 5  is an isometric view of the base of the wash basin of  FIG. 2 ; 
         FIG. 6  is a top plan view of the cleaning station of  FIG. 2 ; 
         FIG. 7  is a bottom plan view of the cover of the of the cleaning station of  FIG. 2 ; 
         FIG. 8  is a side elevation view of the cleaning station of  FIG. 2  loaded with an AFM scanner for cleaning; 
         FIG. 9  is a section view of the cleaning station loaded with an AFM; 
         FIG. 10  is an exploded view of a cleaning station according to another embodiment of the invention; 
         FIG. 10A  is a section view of the cleaning station of  FIG. 10 ; 
         FIG. 11  is an exploded view of a cleaning station according to yet another embodiment of the invention; 
         FIG. 12  is a section view of a cleaning station according to another embodiment of the invention; 
         FIG. 13  is a section view of the cleaning station of  FIG. 12  shown loaded with a scanner for cleaning according to the invention; 
         FIG. 14  is a sectional view of a sealing chamber for sealing the exposed end of a cable of an AFM scanner being cleaned according to a further embodiment of the present invention; 
         FIG. 15  is an isometric top view of an AFM scanner that may be cleaned using the cleaning station of the present invention; 
         FIG. 16  is an isometric bottom view of the AFM scanner of  FIG. 15 ; and 
         FIG. 17  is a section view of the AFM scanner shown in  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is generally directed to a cleaning station for cleaning exposed surfaces of an AFM component, such as a scanner. In this regard, the invention is particularly useful for cleaning AFM components that come into contact with fluid when imaging or collecting data from samples contained in the fluid. While the cleaning station will be described and shown relative to a particular AFM scanner construction, it is understood that the invention is not so limited and thus could be used with other types of scanners or components of a microscopy system. While the cleaning station is believed to be particularly beneficial for cleaning a scanner such as that shown in  FIGS. 15-17  and described more fully in U.S. Ser. No. 13/068,052) the disclosure of which is incorporated herein, the invention may be used with other scanners as well including, but not limited to scanners of less compact design than the scanner shown in  FIGS. 15-17 . 
     Turning now to  FIGS. 2-7 , a cleaning station  20  according to one embodiment of the invention includes a cover  22  and a base  24  that collectively define an enclosure  26 , when the cover  22  is engaged with the base  24 , as best shown in  FIG. 3 . With the illustrated cleaning station  20 , the cover  22  and the base  24  are each disc-shaped, but it is understood that the invention is not so limited. The base  24  provides a surface against which the scanner or other AFM component may be seated when loaded into the cleaning station  20 . In one preferred embodiment, the base  24  includes a pedestal  28  that extends from the floor  30  of the base  24  onto which the scanner may be seated. The pedestal has a tapered surface that mirrors a taper of the scanner shown in  FIGS. 15-17 , and therefore provides a relatively snug seating of the scanner on the base  24 . Additionally, as will be described more fully below, the cover  22  is detached from the base  24  when the scanner is loaded onto the base  24 . The pedestal  28  thus also functions as alignment aid so that the scanner is properly loaded onto the base  24 . 
     The cover  22  has an opening  32  that aligns with the pedestal  28  when the cover  22  is mated to the base  24 . In the illustrated embodiment, the opening is a circular opening but other shaped openings could be used. A gasket  34  is attached to the cover  22  and fits within the opening  32 . In the illustrated embodiment, the gasket  34  is an annular gasket to match the shape of the circular opening  32 . Thus, it is understood that the gasket  34  may have a different shape to accommodate different shaped openings. 
     The opening  32  is sized to receive an end of the AFM scanner and, more particularly, receive the end of the AFM scanner to be cleansed. The inner radial edge  36  of the gasket  34  engages the outer wall of the AFM scanner and provides a seal around the body of the AIM scanner to prevent cleaning fluid and agents from passing through the opening  32  and into the enclosure  26 . The interfacing between the scanner and the cleaning station  20  and, in particular, gasket  34  will be described more fully below with respect to  FIG. 9 . 
     The base  24  has an annular wall  38  that extends from the floor  30  of the base  24 . Threads  40  are formed in a conventional manner around the outer surface of the annular wall  38 . An annular groove  42  is formed in a top edge  44  of the annular wall  38 . An o-ring  46  is seated in the annular groove  42  and is compressed into the annular groove  42  when the cover  22  is threaded onto the base  24 . As shown in  FIGS. 4 and 7 , the cover  22  has outer ring  48  with an outer diameter that is substantially matched to the diameter of the annular wall  38  of the base  24 . The inner surface of the outer ring  48  contains threads  50  that are designed to engage the threads  40  of the base  24  in a conventional manner. As shown in  FIG. 2 , the exterior surface of the outer ring  48  has a series of notches  52  that are spaced apart from one another by ribs  54 . The combination of the ribs  54  and notches  52  effectively create a gripping surface for a user, or machine in an automated system, to grasp the cover  22  and tighten it down onto the base  24  by rotating the cover  22  relative to the base  24 . As best shown in  FIG. 4 , as the cover  22  is tightened down onto the base  24 , the o-ring  46  seated in the annular groove  42  creates a seal between the cover  22  and the base  24 . The o-ring  46  is preferably formed of corrosion resistant material that will not degrade prematurely if exposed to the cleaning agents used to clean the scanner. 
     In one embodiment, the outer ring  48  of the cover  22  is in the form of a rubberized or plastic ring that is resistive to corrosion that may be otherwise caused by the cleaning agents used to clean the scanner. In addition to the ring  48 , the cover  22  has a cap  56  that is rotatable relative to outer ring  48 . As best shown in  FIG. 4 , the cap  56  has a flange  58  that is movable between an “open” position and a “closed” position when the outer ring  48  is rotated relative the outer cap  56 . When the cover  22  is tightened down onto the base  24 , the outer ring  48  provides compression between the annular wall  38  of the base  24  and the cap  56  as best shown in  FIG. 4  at  60 . The outer ring  48  is captive, i.e., rotatable around, but not user separable from the cap  56 . In this regard, the cap  56  does not rotate relative to the base  38  as the cover  22  is tightened onto the base  24 . That is, the outer ring  48  is free to rotate relative to the cap  56  and the interface between a flange of the cap and a cutout of the base, as will be described below, prevent the cap  56  from rotating as the outer ring  48  is threaded onto the base  24 . 
     A cutout  64  is formed at the upper end of the inner surface of the annular wall  38  of the base  24 . This cutout  64  is designed to receive the flange  58  of the cap  56  when the cap  56  is in the open position. The cutout  64  and the flange  58  cooperate to ensure that the cover  22  is properly seated on the base  24  before the cover  22  is tightened down on the base  24 . If the cover  22  is misaligned when it is tightened down on the base  24 , a poor seal may form between the cover  22  and the base  24 . Additionally, the threads  40 ,  50  may otherwise be damaged if a misaligned cover  22  was tightened down onto the base  24 . 
     To assist a user in differentiating between the open and closed position, a marker  66  is formed on the outer ring  48 . The cap  56  has an open mark  68  and a closed mark  70  to identify the open and closed positions, respectively. In this regard, when the outer ring  48  of the cap  56  is rotated so that the open mark  68  aligned with the marker  66  on the outer ring  48 , the flange  58  shall fall into the cutout  64  to properly align and seat the cover  22  on the base  24 . On the other hand, when the closed mark  70  is aligned with the marker  66 , the flange  58  will be misaligned with the cutout  64  thereby preventing the cover  22  from seating properly on the base  24 . Moreover, the association of the open mark  68  and the marker  66  is designed to ensure that the opening  32  aligns with the pedestal  28  when the cover  22  is properly seated on the base  24 . 
     The cap  56  preferably has a raised portion  72  operable as a handle to rotate the cap  56  between the aforementioned open and dosed positions. The shape of the raised portion can be designed to provide for good cleaning fluid run-off. The shape of the raised portion can also prevent fluid from potentially contaminated outside surfaces of the container, or from the hands of the operator, to run onto the surfaces of the AFM component to be cleaned. It is understood that the shape of the raised portion  72  could vary from that illustrated in  FIG. 2 . For example,  FIG. 6  shows the cover  22  with a different shaped raised portion. 
     It is understood that other types of alignment aids could be used to ensure proper alignment of the cover  22  with the base  24  before the cover  22  is tightened onto the base  24 . 
     Turning now to  FIGS. 8 and 9 , the cleaning station  20  is designed to seal fluid sensitive components of a scanner  74  from the cleaning agents that are used to clean the surface of the scanner that is loaded into the fluid medium during sampling. In this regard, the opening  32  is sized so that the exterior surface  76  of the scanner  74  to be cleaned extends through the opening  32  formed in the cover  22 . Gasket  34  tightly engages the outer wall of the scanner  74  and thus seals the components of the scanner  74  extending beneath the plate  56  from being exposed to the cleaning agents during cleaning of surface  76 . 
     Moreover, as best shown in  FIG. 9 , the enclosure  26  formed by the cover  22  and the base  24  is large enough to accommodate the cable  78  that is connected to the electronics of the scanner  74 . As such, the exposed plug  80  of the cable  78 , which is also typically sensitive to water and cleaning agents is also sealed from the cleaning agents during cleaning of the exposed enclosure  26  of the scanner  74 . As will be described more fully below with respect to  FIGS. 15-17 , the scanner  74  has an annular channel  82  formed along its body and the radial edge  36  of the gasket  34  is received in this channel  82  when the scanner  74  is loaded into the opening  32 . 
     In a preferred embodiment, to ready the scanner  74  for cleaning, the cap  56  is first aligned with the outer ring  48 , i.e., the open mark  68  is aligned with marker  66 . This, as described above, ensures proper alignment between the cover  22  and the base  24 . Next, the scanner  74  is passed through the opening  32  so that the surfaces of the scanner  74  to be cleaned extend through the opening  32 . The scanner  74  is passed through the opening  32  until the surfaces of the scanner  74  to be cleaned are exposed. The cable  78  is then collected and laid on the floor  30  of the base  24 , e.g., pedestal  28 . The cover  22  is then brought into contact with the base  24  and tightened down, as described above, to seal the cover  22  onto the base  24 . As the outer ring  48  is rotatable relative to the cap  56 , the cover  22  can be tightened down onto the base  24  without rotating the scanner  74  seated on the base  24 . The combination of the gasket  34  and the o-ring  46  collectively seal the enclosure  26 , and thus the sensitive electrical components of the scanner  74 , from the cleaning agents and tools that are used to clean the exposed surface  76  of the scanner  74 . 
     In an alternate process, the scanner  74  can be loaded onto the base  24 , e.g., pedestal  28 , the cable  78  collected, and placed on the floor  30  of the base  24 . The cap  56  and the outer ring  48  may be manually aligned to ensure a proper lit of the cover  22  with the base. Thereafter, the cover  22  is lowered onto the base  24  with the opening  32  aligned with the scanner  74 . As the outer ring  48  is rotated, the cover  22  is lowered relative to the scanner  74 , which causes the scanner  74  to extend through the opening  32 . The gasket  34  engages the outer surface of the scanner  74 , as previously described. The outer ring  48  is rotated until the cover  22  is tightened down onto the base  24  thereby sealing the enclosure  26  encasing the portion of the scanner  74  containing fluid sensitive components and the cable  78 . 
     Turning now to  FIGS. 10 and 10A , a cleaning station  84  according to another embodiment of the invention is shown. This cleaning station  84  is generally similar to cleaning station  20  described above in that it has a cover  86  and a base  88  that when mated together collectively define an enclosure. The cover  86  has an opening  90  designed to receive an exposed end of scanner  74  to be cleaned. A gasket  92  is sealed in the opening  90  and engages tightly against the outer surface of the scanner  74  when the scanner  74  is loaded into the cleaning station  84 . Rather than using a threaded engagement to couple the cover  86  to the base  88 , cleaning station  84  uses compression screws  94 . More particularly, the cover  86  has ledges  96  with holes  98  bored at selected positions therealong. Similarly, the base  88  has threaded holes  100  that align with holes  98  when the cover  86  is properly aligned with the base  88 . Screws  94  can then be inserted through the respective holes and tightened down in a conventional manner using a driver (not shown). The screws may also be thumb screws. The screws may also be captive on the component not containing the mating threads. To seal the cover  86  and the base  88 , an o-ring  102  is provided that sits in an annular channel  104  formed in the base  88 . Hence, when the cover  86  is tightened down onto the base  88 , a tight seal is formed by the o-ring  102  to prevent the ingress of fluid into the enclosure collectively defined by the cover  86  and the base  88 . In a preferred embodiment, an alignment podium  106  extends from the floor  108  of the base  88 , and is designed to provide a structure onto which the scanner  74  can be seated when the scanner  74  is loaded into the cleaning station  84 . 
     Cleaning station  84  allows the scanner  74  to be loaded in a slightly different manner than that described above with respect to cleaning station  20 . More particularly, in one preferred mounting method, the cover  86  is detached from the base  88  to expose the alignment podium  106 . The scanner  74  is then seated onto the alignment podium  106 . The cable  78  is collected and placed on the floor  108  of the base  88 . The cover  86  is then aligned with the base  88  and lowered into position. This lowering of the cover  86  causes a portion of the scanner  74  to pop through the opening  90  in the cover  86 . And, as described above, the gasket  92  tightly engages the outer surface of the scanner  74  to provide a sealed engagement of the scanner  74  with the cover  86 . The compression screws  94  may then be inserted into the mounting holes and tightened, as described above, to compress the cover  86  and the base  88  against o-ring  102  and provide a tight seal therebetween. 
     It is also contemplated however that the scanner  74  could be loaded into cleaning station  84  in a manner similar to that described with respect to cleaning station  20  in that the scanner  74  is engaged with the cover  86  and then the cover is mated to the base  88 . 
     Turning now to  FIG. 11 , a cleaning station  110  according to another embodiment of the invention is shown. Cleaning station  110  is similar to the cleaning stations heretofore described in that it comprises a cover  112  and a base  114  that mate together to form an enclosure. The base  114  has an annular groove  116  adapted to receive an o-ring  118  that seals the interface between the cover  112  and the base  114 . Rather than outwardly extending ledges having holes to facilitate a compression fit of the cover  112  to the base  114 , this cleaning station  110  is constructed such that the inner annular wall  120  of the base  114  has inwardly extending lobes  122  with holes  124  formed therein. The holes  124  align with holes  126  formed in the cover  112 . Fasteners  128  may then be passed through the aligned holes  126 ,  128  to tightly fit the cover  112  against the base  114 . Preferably, the fasteners  128  pass through pairs of small seals  130 ,  132  to prevent fluid from passing through holes  126 . 
     The cover  112  has an opening  134  through which the scanner  74  may be passed in a manner similar to that described above. A gasket  136  is attached to the opening  134  to prevent the ingress of fluid through the opening  134  when the scanner  74  is loaded for cleaning. As shown in  FIG. 11 , it is contemplated that an additional gasket  138  may be attached to the underside of the cover  112  to provide additional sealing of the opening  134 . Although now shown in  FIG. 11 , it is contemplated that that cleaning station  110  may have an alignment pedestal similar to that described above. 
     Turning now to  FIG. 12 , a cleaning station  140  according to another embodiment of the present invention is shown. Cleaning station  140  has a platform  142  that sits atop a work surface  144 . An annular groove  146  is formed in the outer surface of the platform  142 . A seal  148 , such a gasket, is positioned in the annular groove  146  and prevents the ingress of fluid into the scanner  74  when the scanner  74  is loaded onto the platform  142 , as best shown in  FIG. 13 . In this embodiment, it is expected that the fluid sensitive components are mounted adjacent the upper end of the scanner  74  (when the scanner is loaded onto the platform  142 ) in a cavity  150  effectively defined between exposed surface  76  of the scanner  74  and the upper surface  152  of the platform  142 . The seal  148  is placed adjacently below the upper surface  152  to prevent the ingress of fluid into the cavity  150  that is formed between the platform  142  and the scanner  74 . 
     In this embodiment, which is a somewhat simplified version of cleaning station  20 ,  84 , the plug  80  of the scanner cable  78  remains exposed. Accordingly, the present invention also provides for a sealing container  154  for the plug  80 , one embodiment of which is shown at  FIGS. 13 and 14 . In the illustrated embodiment, the sealing container  154  includes a pair of mating shells  156 ,  158  that collectively define a chamber  160  for receiving the plug  80 . Upper shell  156  is preferably hinged to lower shell  158  at joint  162  that is sealed in a conventional mariner. A slot  164  is formed between the upper shell  156  and the lower shell  158  that allows the cable  78  to extend from the plug  80  and out of the sealing container  154 . A gasket  166  is positioned in the slot  164  to prevent the ingress of fluid through slot  164  and into the chamber  160 . It will thus be appreciated that the combination of cleaning station  140  and sealing container  154  prevent exposure of fluid sensitive components of the scanner  74  from being exposed to cleaning agents and fluids during cleaning of the scanner  74 . 
     As described above, the washing stations of the present invention can be used to clean several different types of scanners. One exemplary scanner is shown in  FIGS. 15-17 , which is described in U.S. Ser. No. 13/068,052 in greater detail. 
     Turning now to  FIGS. 15-17 , scanner  74  includes a body  200  having an inner surface  206  and an outer surface  208  which essentially has a nozzle shape. Extending from scanner body  200  is scanner cable  78  which electronically connects scanner  74  to AFM head (not shown), thus providing control and communication between head and scanner  74 . Body  200  includes a first or top end  202  that is open and which configured to be rigidly coupled to the AFM head. Opposite first end  202  is a second or bottom end  204  that is closed and sealed so that it may be introduced to varying environments, including fluid, while protecting the sensitive scanner components housed within body  200 . A probe holder  360  is provided at second end  202 . Probe holder  360  includes a retaining clip  362  for holding probe assemblies during AFM operation, and is preferably formed integrally with second end  202 . 
     First end  202  includes a rim  212  that is formed with a pair of annular slots  214 ,  216 , the slots extending a length along rim  212  and being disposed about 180 degrees from one another. Slots  214 ,  216  terminate in corresponding openings  218 ,  220  that are adapted to receive indexing pins (not shown) coupled to the head and extending downwardly from the AFM head. When scanner  74  is so coupled, proper orientation of scanner  74 , and correspondingly, the probe holder and probe(s) supported by scanner  74  is required. When coupling scanner  74  to the AFM head the aforementioned pins ride in corresponding slots  214 ,  216  as the AFM user rotates the scanner until pins engage openings  218 ,  220 . When pins drop into openings  218 ,  220  the scanner is properly oriented and further rotation of the scanner is prevented. In this position, scanner  74  is rigidly mounted to the AFM head, as further described in U.S. Ser. No. 13/068,052. The scanner  74  also includes a sensor  264  including a substrate  268 . 
     Turning to  FIG. 17 , more detail of scanner  74  and corresponding cable  78  is illustrated, along with further detail concerning probe holder  360  bonded to scanner  74 . In particular, cable  78  is coupled to scanner  74  with an interconnect PCB  350  disposed between the two for communication between scanner  74  and the fast scanning AFM head. An insulator  352  is bonded to a bottom surface of second body portion  203  of body  200  of scanner  74 . A wedge  354  is further bonded to insulator and provides a selected amount of tilt for a probe device held by the probe holder. A probe clip  360  is formed integrally with probe holder  360 , clip  362  operating to hold probes  364  against wedge  354 . Notably, a tapping piezo electric assembly  366  is formed in a cavity (not numbered) formed in wedge  354 . Appropriate wiring is provided to excite tapping piezo electric assembly  364 . Because probe holder  360  is formed integrally with the scanner  74 , a rigid structure is provided having significantly greater resonance than conventional AFMs. 
     Overall, referring again to  FIG. 13 , the scanner mount and compact probe holder design of the scanner significantly improve what was a significant limitation on system resonance. Rather than some known systems which utilize a mechanically non-rigid coupling between probe holder and scanner (e.g., pins extending downwardly from a piezoelectric tube into probe holder openings), in the present preferred embodiments, the tapered surface  300  of the scanner  74  together with a tapered surface of the objective (not shown) provide a rigid mechanical connection between the two. This rigid coupling is provided by maintaining significant surface area of scanner  74  in direct contact with an outer surface of free end portion of the objective (not shown). As shown in  FIG. 13 , the length “Q” of the cylindrical interface between the two structures is substantial, providing large surface area of contact between the two components, thus yielding a very rigid structure. This facilitates high resonance capability. 
     Preferably, a angle of taper, α, is preferably between about 15° and 35°, and ideally about 22°, is employed. The actual amount of taper in the arrangement is a trade-off between ease-of-use and position repeatability of scanner  74 . If the angle is much smaller than 22°, the scanner  74  cannot be readily removed by hand. If, on the other hand, an angle much larger than 22° is employed, scanner position on the taper will not likely be as accurate and repeatable. 
     As further shown in  FIG. 17 , an annular groove  400  formed adjacent the second body portion  203  of the scanner body. As described above, groove  400  effectively functions as a receiver for the leading of a gasket, e.g., gasket  34  of cleaning station  20 . When the leading edge of the gasket seats in groove  400 , a relatively tight seal is formed between the gasket and the scanner body which is substantially impervious to the flow of fluid, i.e., cleaning agents. 
     The present invention has been described with respect to cleaning stations for sealing fluid sensitive components of a scanner from contact with potentially damaging cleaning agents and fluids. While these cleaning stations have been shown and described with respect to cleaning one scanner at a time, it is understood that the cleaning stations of the present invention could be constructed so that multiple scanners could be cleaned at a time.