Patent Publication Number: US-7220973-B2

Title: Modular manipulation system for manipulating a sample under study with a microscope

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 10/173,543, filed on Jun. 17, 2002 now U.S. Pat. No. 6,891,170, and is related to U.S. patent application Ser. No. 10/173,542, concurrently filed on Jun. 17, 2002, entitled “MANIPULATION SYSTEM FOR MANIPULATING A SAMPLE UNDER STUDY WITH A MICROSCOPE,” the disclosures of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates in general to a manipulation system for manipulating a sample under study with a microscope, and more particularly to a modular manipulation system that preferably comprises a platform capable of receiving a plurality of manipulation modules for manipulating a sample. 
     BACKGROUND OF THE INVENTION 
     Much development is being achieved on the micrometer (μm) and nanometer (nm) size scales. For example, much work is being performed at these small size scales in such scientific fields as biology, medicine, physics, chemistry, electronics, engineering, and nanotechnology to, for example, study objects (e.g., materials, organisms, viruses, bacteria, etc.), create new objects, and/or assemble objects together with great precision. 
     To perform manipulation of objects on such a small size scale, it is often necessary to use microscope equipment to aid in observing the objects. For instance, the smallest object that human beings can see with the unaided eye is about 0.1 millimeter (mm). With a good light microscope (also referred to as an “optical microscope”), an image may be magnified up to about 1500 times. However, magnification achievable with light microscopes is limited by the physics of light (i.e., the wavelength of light) upon which the operation of such microscopes is based. For example, light microscopes have relatively limited resolving power (ability to distinguish clearly between two points very close together). The resolving power, α, is measured by the angular separation of two point sources that are just detectably separated by the instrument. The smaller this angle, the greater the resolving power. Thus, in general α=1.22λ/D, where λ is the wavelength of the light used and D is the diameter of the objective lens in meters (m). The best resolving power that can be achieved with a light microscope is around 0.2 μm. Points closer together than this cannot be distinguished clearly as separate points using a light microscope. 
     Of course, by reducing the wavelength of the radiation used in a microscope to view an object, the resolution obtainable can be improved. Thus, electron microscopes have been developed that use a beam of electrons, rather than light, to study objects too small for conventional light microscopes. Max Knoll and Ernst Ruska constructed the first electron microscope around 1930. In general, electron microscopes use a beam of electrons to irradiate a sample under study, wherein the wavelength of such electron beam (generally resulting from magnetic forces acting on the beam) is much smaller than the wavelength of light used in light microscopes. Accordingly, the amount of magnification (and the resolving power) achievable with an electron microscope is much improved over that of light microscopes. 
     Modem electron microscopes typically comprise: (1) an electron gun to produce a beam of accelerated electrons; (2) an image producing system that includes electrostatic lenses (e.g., generally formed by electromagnetic or permanent magnets) and metal apertures to confine and focus the electron beam, pass it through, or over, the surface of the specimen and create a magnified image; (3) an image viewing and recording system, which typically includes photographic plates or a fluorescent screen; and (4) a vacuum pump to keep the microscope under high vacuum, as air molecules may deflect electrons from their paths. The development of the electron microscope has had a massive impact on knowledge and understanding in many fields of science. Modem electron microscopes can view detail at the atomic level with sub-nanometer resolution (e.g., 0.1 nm resolution, which is 1000 times better than conventional light microscopes) at up to a million times magnification. 
     Various different types of electron microscopes have been developed. Such electron microscopes generally work on the above-described principles of using a directed beam of electrons, as opposed to light, for studying samples. One type of electron microscope is the transmission electron microscope (TEM). In a TEM, electrons are transmitted through a thinly sliced specimen and typically form an image on a fluorescent screen or photographic plate. Those areas of the sample that are more dense transmit fewer electrons (i.e., will scatter more electrons) and therefore appear darker in the resulting image. TEMs can magnify up to one million times and are used extensively, particularly in such scientific fields as biology and medicine to study the structure of viruses and the cells of animals and plants, as examples. 
     Another type of electron microscope is the scanning electron microscope (SEM). In an SEM, the beam of electrons is focussed to a point and scanned over the surface of the specimen. Detectors collect the backscattered and secondary electrons coming from the surface and convert them into a signal that in turn is used to produce a realistic, three-dimensional image of the specimen. During the scanning process, the detector receives back fewer electrons from depressions in the surface, and therefore lower areas of the surface appear darker in the resulting image. SEMs generally require the specimen to be electrically conducting. Thus, specimens that are not conducting are typically coated (e.g., using a sputter coater) with a thin layer of metal (often gold) prior to scanning. SEMs can magnify up to around one hundred thousand times or more and are used extensively, particularly in such scientific areas as biology, medicine, physics, chemistry, and engineering to, for example, study the three-dimensional (“3-D”) structure of surfaces from metals and ceramics to blood cells and insect bodies. 
     In addition to the above-described light and electron microscopes, various other types of microscopes have also been developed to aid in the study of micro- and/or nano-scale objects, including without limitation scanning probe microscopes (SPMs). Various types of SPMs have been developed, such as atomic force microscopes (AFMs), scanning tunnelling microscope (STM), and near field optical scanning microscope (NOSM), as examples. Microscopes have traditionally been used for imaging (e.g., viewing specimens). However, to provide greater utility, a recent trend has been to include a manipulator mechanism that may be used in conjunction with the microscope for manipulating a specimen being imaged by the microscope. For example, manipulator mechanisms, such as probes, have been developed to be integrated within an SEM for manipulating a sample being imaged by the SEM. For instance, LEO ELECTRON MICROSCOPY LTD. has proposed certain manipulating mechanisms for use with an SEM. Further, manipulator mechanisms, such as probes, have been developed to be integrated within a TEM for manipulating a sample being imaged by the TEM. For instance, NANOFACTORY INSTRUMENTS has proposed certain in situ probes for TEMs. 
     BRIEF SUMMARY OF THE INVENTION 
     As described above, manipulating mechanisms (e.g., probes) have been developed for use with microscopes, such as SEMs and TEMs, in order to allow manipulation of a sample being imaged by such microscopes. However, manipulating mechanisms of the existing art comprise relatively inflexible configurations. For example, such manipulating mechanisms generally do enable a user flexibility in configuring a plurality of desired manipulator mechanisms within a system for manipulating a sample under study with a microscope. Further, many such manipulating systems are fixedly integrated with a microscope. Also, such manipulation systems often require modifications to a microscope with which they are coupled that interfere with the traditional functionality of such microscope. Further still, most manipulation systems of the prior art comprise relatively few (e.g., one) manipulating mechanism (e.g., probe) that is operable for manipulating a sample. 
     The present invention is directed to a modular manipulation system and method for using such modular manipulation system for manipulating a sample under study with a microscope. According to at least one embodiment of the present invention, a platform is provided that comprises an interface to a microscope, a sample stage, and a plurality of interfaces for receiving manipulator modules for manipulating a sample arranged on the sample stage. In certain embodiments, the platform&#39;s interface to a microscope enables the platform to be detachably coupled to such microscope. For instance, the platform is, in certain implementations, suitable for being inserted into a sample chamber of the microscope. Further, the plurality of interfaces for receiving manipulator modules are each preferably capable of detachably coupling a manipulator module to the platform. Thus, in a preferred embodiment, a user may selectively couple one or more desired manipulator modules to the platform to enable a desired type of manipulation to be performed on a sample under study. Accordingly, a preferred embodiment enables great flexibility in configuring a manipulation system in a desired manner. 
     According to at least one embodiment of the present invention, a system is provided that comprises a platform having a sample stage and an interface for coupling to a microscope such that a sample arranged on the sample stage can be imaged by the microscope. The system further comprises a plurality of manipulator modules detachably coupled to the platform for manipulating a sample arranged on the sample stage. Preferably, the platform is suitable for coupling at least to a scanning electron microscope (SEM), but may be suitable for coupling to another type of microscope in certain implementations. Preferably, the manipulator modules each comprise an end-effector and a drive mechanism for driving movement of its respective end-effector. 
     According to at least one embodiment of the present invention, a portable sample holder is provided for holding a sample for presentation to a microscope. The portable sample holder comprises a stage for receiving a sample. The portable sample holder further comprises a plurality of interface sites, each of such plurality of interface sites for receiving a manipulator module, wherein the manipulator module comprises an end-effector and a drive mechanism for driving movement of the end-effector for manipulating a received sample. The portable sample holder further comprises an interface for coupling with a microscope. 
     According to at least one embodiment of the present invention, a method of manipulating a sample under study with a microscope is provided. The method comprises selecting at least one manipulator module to use in manipulating a sample. The method further comprises coupling each of the selected manipulator module(s) to one of a plurality of interface sites on a manipulator platform. The method further comprises arranging a sample on the manipulator platform, and interfacing the manipulator platform with a microscope such that the sample arranged thereon can be imaged by the microscope. The method further comprises using the manipulator module(s) coupled to the manipulator platform to manipulate the sample. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which: 
         FIG. 1  shows a typical configuration of a TEM; 
         FIG. 2  shows a typical configuration of an SEM; 
         FIG. 3  shows an example configuration of a preferred embodiment of the present invention in block diagram form; 
         FIG. 4A  shows an example pool of various manipulator modules that may be selectively coupled to a manipulation platform; 
         FIG. 4B  shows an example pool of various end-effectors that may be selectively coupled to a manipulator module; 
         FIG. 5  shows an example implementation of a preferred embodiment of a manipulation platform; 
         FIG. 6  shows an example implementation of a preferred embodiment of a manipulation platform coupled with an SEM; and 
         FIG. 7  shows an operational flow diagram that illustrates an example of how certain embodiments of the present invention may be utilized. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Various embodiments of the present invention are now described with reference to the above figures, wherein like reference numerals represent like parts throughout the several views. According to embodiments of the present invention, a manipulation system is provided for use in manipulating a sample that is under study with a microscope. Preferably, the manipulation system is modular in that various different types of manipulator modules may be selectively coupled with a platform to enable the platform to be configured for performing a desired type of manipulation. 
     “Manipulation” is used herein in its broadest sense, and is not intended to be limited solely to actions that result in a change in the sample under study. Rather, certain types of manipulation may not alter the sample at all, but may instead aid in observing the sample (e.g., measuring certain characteristics of the sample). For example, Webster defines “manipulate” as “to treat or operate with the hands or by mechanical means especially in a skillful manner”. MERRIAM-WEBSTER&#39;S COLLEGIATE DICTIONARY, Deluxe Edition, 1998 (ISBN 0-87779-714-5). As used herein, the term “manipulate” (as well as variances thereof, such as “manipulation”, etc.) is intended to encompass Webster&#39;s definition in that it includes “treating” or “operating” on a sample, which does not necessarily result in a modification to the sample (but may instead simply aid in observing a characteristic thereof). However, as described further below, the types of manipulation are not intended to be limited to being performed by “mechanical means”, but are also intended to encompass various other types of manipulating means, such as electrical means, etc. 
     In certain embodiments of the present invention, a manipulation system comprises a platform having a sample stage and an interface for coupling to a microscope such that a sample arranged on the sample stage can be imaged by the microscope. The manipulation system may further comprise a plurality of manipulator modules detachably coupled to the platform for manipulating a sample arranged on the sample stage. Most preferably, the platform is capable of coupling at least with an SEM. The manipulator modules may each comprise an end-effector, such as a probe, gripper, etc., and a drive mechanism for driving movement of the end-effector. Preferably, each manipulator module is independently operable to drive the operation of its respective end-effector. For instance, a platform may be configured with a plurality of manipulator modules coupled thereto, wherein each manipulator module is independently operable to impart translational movement to its respective end-effector in at least three dimensions. 
     In certain embodiments, the manipulation system comprises a manipulation platform (which may be referred to as a “sample holder”) that is portable. Preferably, such manipulation platform is capable of being coupled to a microscope in order to add desired sample manipulation capability to the microscope without requiring modification of the microscope itself. That is, preferably the manipulation platform is implemented such that it can be coupled to a microscope to enable not only imaging of a sample with the microscope, but also manipulation of such sample using the manipulation platform, and the manipulation capability is preferably added to a microscope without requiring modification of the microscope. Rather, according to certain embodiments, a manipulation platform (or “sample holder”) that comprises manipulation modules coupled thereto may be detachably coupled to a microscope in a manner that does not require modification of the microscope itself. For example, microscopes such as TEMs and SEMs typically comprise a sample chamber for receiving a sample holder, and certain embodiments of the present invention provide a sample holder (or “manipulation platform”) that is suitable for interfacing with such a sample chamber comprises a stage for receiving a sample to be imaged by a microscope and further comprises one or more manipulator modules for manipulating the sample. Therefore, in certain embodiments, in situ manipulation is provided by the sample holder (or “manipulation platform”), which can be readily dislodged from a microscope (e.g., from the microscope&#39;s sample chamber) without introducing any interference for other microscope users desiring to operate the microscope in standard way, thus allowing such users access to the full functionality provided by the microscope instrument itself. 
     For instance, in certain embodiments, a portable sample holder for holding a sample for presentation to a microscope comprises a stage for receiving a sample. The sample holder further comprises a plurality of interface sites, each of which are for receiving a manipulator module. As mentioned above, a manipulator module may comprise an end-effector and a drive mechanism for driving movement of the end-effector for manipulating a sample received on the sample stage. Thus, a manipulator module that is controllably operable for manipulating a sample may be selectively coupled to each of the plurality of interface sites to configure the portable sample holder for a desired type of sample manipulation. 
     The portable sample holder further comprises an interface for coupling with a microscope. Thus, the sample holder may be used to present a sample to a microscope for imaging, and the sample holder may comprise manipulator module(s) selectively coupled therewith for manipulating such sample. Preferably, the sample holder (or “manipulation platform”) of embodiments of the present invention is capable of interfacing with a microscope in a manner that does not otherwise interfere with the normal operation (e.g., imaging functionality) of such microscope. Thus, the manipulation system may preferably be interfaced to a microscope, such as an SEM, to provide the ability to manipulate a sample under study, but does not interfere with a user desiring to utilize the standard functionality (e.g., imaging functionality) of the microscope. For instance, a user may either remove the manipulation platform from a microscope and replace it with a traditional sample holder for such microscope to enable traditional operation of the microscope, or the user may simply not use the manipulator modules of the manipulation platform but instead use only the traditional functionality of the microscope itself (e.g., imaging functionality). 
     As described above, microscopes play a vital role in analyzing and otherwise working with samples at a micrometer and/or nanometer scale. Various different types of microscopes, including without limitation light microscopes, electron microscopes (e.g., TEMs, SEMs, etc.), and SPMs have been developed for studying samples at such small size scales. While alternative embodiments of the present invention may be applied to any one or more types of microscopes now known or later developed, a preferred embodiment is applicable to electron microscopes. As described further below, a most preferred embodiment is applicable at least to SEMs. Accordingly, to better understand some of the advantages offered by certain embodiments of the present invention, examples of electron microscopes available in the existing art are described in greater detail hereafter in conjunction with  FIGS. 1–2 . More particularly, a typical configuration of a TEM is described with  FIG. 1 , and a typical configuration of an SEM is described with  FIG. 2 . Thereafter, example implementations of embodiments of the present invention are described in conjunction with  FIGS. 3–5 , and an example implementation of a preferred embodiment implemented with an SEM is described in conjunction with  FIG. 6 . Thereafter, an example of how embodiments of the present invention may be used to perform manipulation of a sample under study with a microscope is described in conjunction with the operational flow diagram of  FIG. 7 . 
     While typical configurations of a TEM and SEM are described below in conjunction with  FIGS. 1–2 , it should be understood that embodiments of the present invention are not limited to the example configurations described. Rather, certain embodiments of the present invention may be utilized with any other configuration of TEMs and SEMs now known or later developed. Additionally, while a preferred embodiment provides a manipulation system that is capable of being utilized at least with an SEM, other embodiments of the present invention may be configured such that they may be utilized with one or more other types of microscopes now known or later developed (including without limitation light microscopes, SPMs and/or other types of electron microscopes, such as TEMs) in addition to or instead of SEMs. 
     As described briefly above, electron microscopes are scientific instruments that use a beam of highly energetic electrons to examine specimens on a very fine scale. This examination can yield a great deal of information, including the following: (1) Topography: the surface features of a specimen or “how it looks”, its texture; direct relation between these features and materials properties (hardness, reflectivity, etc.); (2) Morphology: the shape and size of the particles making up the specimen; direct relation between these structures and materials properties (ductility, strength, reactivity, etc.); (3) Composition: the elements and compounds that the specimen is composed of and the relative amounts of them; direct relationship between composition materials properties (melting point, reactivity, hardness, etc.); and (4) Crystallographic Information: how the atoms are arranged in the specimen; direct relation between these arrangements and materials properties (conductivity, electrical properties, strength, etc.). 
     Electron microscopes were developed due to the limitations of light microscopes, which are limited by the physics of light (i.e., the wavelength of light) to 500× or 1000× magnification and a resolution of approximately 0.2 μm. In the early 1930&#39;s this theoretical limit had been reached with light microscopes, and there was a scientific desire to see the fine details of the interior structures of organic cells (nucleus, mitochondria, etc.). This required 10,000× plus magnification, which was not possible to achieve using light microscopes. To overcome the limitations of light wavelengths utilized in light microscopes, electron microscopes were developed that utilize a beam of electrons to irradiate the specimen. 
     In general, electron microscopes function much like light microscopes, except they use a focused beam of electrons instead of light to “image” the specimen and gain information as to its structure and composition. The operation of electron microscopes generally involves the following: (1) a stream of electrons is formed (e.g., by an electron source) and accelerated toward the specimen using a positive electrical potential; (2) this stream is confined and focused using metal apertures and magnetic lenses into a thin, focused, monochromatic beam; (3) this beam is focused onto the sample using electrostatic lenses (generally magnetic lenses); and (4) interactions occur inside the irradiated sample, affecting the electron beam. 
     Turning first to  FIG. 1 , a schematic of an example configuration of a TEM  100  is shown. The TEM was the first type of electron microscope to be developed, and is patterned on the Light Transmission Microscope, except that a focused beam of electrons is used instead of light to “see through” the specimen. A TEM works much like a slide projector. A slide projector shines a beam of light through (transmits) the slide, as the light passes through the slide it is affected by the structures and objects on the slide. These effects result in only certain parts of the light beam being transmitted through certain parts of the slide. This transmitted beam is then projected onto the viewing screen, forming an enlarged image of the slide. TEMs generally work much the same way, except that they shine a beam of electrons (rather than light) through the specimen (as with the slide in a slide projector system). Whatever part is transmitted is typically projected onto a phosphor screen for the user to see. A more technical explanation of a typical TEM is described further below in conjunction with  FIG. 1 . 
     As shown in the example configuration of  FIG. 1 , TEM  100  comprises an electron source  101 , which may comprise an electron gun, for producing a stream of monochromatic electrons  102 . The stream  102  is focused to a small, thin, coherent beam by the use of condenser lenses  103  and  104 . The first condenser lens ( 103 ), which is usually controlled by the “spot size knob” (not shown) of the TEM, largely determines the “spot size” (i.e., the general size range of the final spot that strikes the sample). The second lens ( 104 ), which is usually controlled by the “intensity or brightness knob” (not shown) of the TEM, actually changes the size of the spot on the sample (e.g., changing it from a wide dispersed spot to a pinpoint beam). The beam  102  is restricted by the condenser aperture  105  (usually user selectable), knocking out high angle electrons (e.g., those far from the optic axis  114 ). The beam  102  strikes the sample (or “specimen”)  106  and parts of it are transmitted. This transmitted portion of beam  102  is focused by the objective lens  107  into an image. 
     Optional objective and selected area metal apertures (labeled  108  and  109 , respectively) may be included to restrict the beam. The objective aperture  108  may enhance contrast by blocking out high-angle diffracted electrons, and the selected area aperture  109  may enable the user to examine the periodic diffraction of electrons by ordered arrangements of atoms in the sample  106 . The image is passed down the column through the intermediate and projector lenses  110 ,  111 , and  112 , being enlarged along the way. The image strikes the phosphor image screen  113  and light is generated, allowing the user to see the image. Typically, the darker areas of the image represent those areas of the sample  106  through which fewer electrons were transmitted (i.e., areas of the sample  106  that are thicker or denser), and the lighter areas of the image represent those areas of the sample  106  through which more electrons were transmitted (i.e., areas of the sample  106  that are thinner or less dense). 
     As further shown in the schematic of  FIG. 1 , a TEM typically comprises a sample chamber  115  into which a sample  106  is placed for imaging. For instance, a sample holder that is removable from chamber  115  may comprise a stage on which sample  106  may be placed. Thus, sample  106  may be placed on the stage of a sample holder, and the sample holder may then be inserted into sample chamber  115 . Sample chamber  115  comprises a defined interface for receiving such a sample holder. For example, TEM sample chambers typically comprise an interface to accept a standard sample holder of approximately 3 mm in thickness, approximately 9 mm in width and approximately 9 centimeters (cm) in length for loading a thin sample generally having approximately 3 mm in diameter. 
     Turning to  FIG. 2 , an example configuration of an SEM is shown.  FIG. 2  shows a high-level block diagram  200 A and a schematic representation  200 B of a typical configuration of an SEM. As shown, an SEM comprises an electron source  201 , which may comprise an electron gun, for producing a stream of monochromatic electrons  202 . Alignment control  203  is utilized to align the direction of the generated stream  202  with the below-described components of the SEM. 
     The stream  202  is condensed by the first condenser lens  205 , which is usually controlled by the “coarse probe current knob” (not shown) of the SEM. This lens  205  is used to both form the beam and limit the amount of current in the beam. It works in conjunction with the condenser aperture  206  to eliminate the high-angle electrons from the beam. The beam is constricted by the condenser aperture  206  (usually not user selectable), eliminating some high-angle electrons. The second condenser lens  207  forms the electrons  202  into a thin, tight, coherent beam and is usually controlled by the “fine probe current knob” (not shown) of the SEM. 
     A user-selectable objective aperture  208  further eliminates high-angle electrons from the beam. A set of coils  209  then “scan” or “sweep” the beam in a grid fashion, dwelling on points for a period of time determined by the scan speed (usually in the microsecond range). The final lens, the objective lens  210 , focuses the scanning beam onto the part of the sample (or specimen)  211 , as desired. When the beam strikes the sample  211  (and dwells for a few microseconds) interactions occur inside the sample and are detected with various instruments. For instance, secondary and/or backscattered electrons  216  are detected and amplified by detector and amplifier  217 . Before the beam moves to its next dwell point, these instruments (e.g., detector and amplifier  217 ) essentially count the number of interactions and display a pixel on a display  218  (e.g., cathode ray tube (CRT)) whose intensity is determined by the counted number of interactions (e.g., the more reactions the brighter the pixel). This process is repeated until the grid scan is finished and may then be repeated. The entire pattern may be scanned 30 times per second, for example. Thus, the resulting image on display  218  may comprise thousands of spots (or pixels) of varying intensity that correspond to the topography of the sample  211 . 
     As further shown in the block diagram  200 A, an SEM typically comprises a sample chamber  214  into which a sample  211  is placed for imaging. For instance, a sample holder that is removable from chamber  214  may comprise stage  213  on which sample  211  may be placed. Thus, sample  211  may be placed on stage  213  of a sample holder, and the sample holder may then be inserted into sample chamber  214 . Sample chamber  214  comprises a defined interface  215  for receiving such a sample holder. The defined interface  215  for an SEM is generally different than the defined interface of the sample chamber of commercially available TEMs, such as the interface described above with  FIG. 1  for sample chamber  115  of TEM  100 . For example, SEM sample chambers typically comprise an interface to accept relatively large samples, if needed, in the space allowed inside the chamber, such as approximately 15 cm by 15 cm by 6 cm. Usually, motorized stage  212  is included in the SEM to enable movement of stage  213  within sample chamber  214 . Also, pneumatic air lock valve  204  is typically utilized to create a vacuum within the SEM once a sample  211  has been inserted into sample chamber  214 , as air molecules may deflect electrons of the generated beam from their intended paths. 
     Turning now to  FIG. 3 , an example configuration of a preferred embodiment of the present invention is shown as a block diagram. In this example configuration, the manipulation system comprises a manipulation platform  10  that includes a base  6  on which a plurality of manipulator module interface sites are arranged, such as sites  1 ,  2 ,  3 , and  4 . Each of the manipulator module interface sites  1 – 4  are capable of receiving a manipulator module, as described more fully below. While four such interface sites are shown in the example configuration of  FIG. 3 , it should be understood that in alternative configurations a different number of such interface sites (either fewer than or greater than 4) may be implemented. However, as described in greater detail below, it is most preferable for platform  10  to include at least four manipulator module interface sites (such as sites  1 – 4  shown in the example of  FIG. 3 ), as having at least four manipulator modules coupled to such platform may allow for particular types of manipulations (e.g., measurements, characterizations, etc.) on a sample to be achieved that are not readily achievable with less than four manipulator modules. 
     Platform  10  preferably comprises a sample stage  5  for receiving a sample to be studied using a microscope. Thus, manipulator modules may be coupled to one or more of manipulator module interface sites  1 – 4 , as described more fully below, to perform manipulation of a sample arranged on sample stage  5 . Platform  10  further comprises an interface  7  that enables base  6  to be coupled to a microscope such that a sample arranged on sample stage  5  can be imaged by such microscope. Thus, for example, once platform  10  is coupled to a microscope, a sample arranged on sample stage  5  may be imaged as manipulator module(s) arranged at one or more of interface sites  1 – 4  are utilized to manipulate the sample. 
     As further shown in  FIG. 3 , a control system  8  may be coupled to platform  10  to enable a user to control the operation of manipulator module(s) coupled to interface sites  1 – 4  in order to manipulate a sample in the manner desired. Control system  8  may comprise any suitable processor-based system, such as a personal computer (PC), that is capable of controlling the operation of manipulator module(s) coupled to interface sites  1 – 4 . For example, a user may input commands (e.g., via a keyboard, pointer device, joystick, etc.) to control system  8 , and in response to such input commands, control system  8  may communicate command signals (e.g., electrical signals) to the appropriate manipulator modules coupled to platform  10  in order to control the operation of such manipulator modules. For instance, communication paths (not shown in  FIG. 3 ), such as conductive (e.g., metal) traces, may be provided on platform  10  to each of manipulator module interfaces  1 – 4 , and control system  8  may interface with platform  10  in a manner that enables command signals to be communicated from such control system  8  to one or more of such manipulator module interfaces via the communication paths. 
     Of course, suitable software may be executing on control system  8  to control the manipulator modules coupled to platform  10 . For example, software may be executing on control system  8  to generate the appropriate command signals to be communicated to one or more of manipulator module interface sites  1 – 4  responsive to user input to control system  8  and/or responsive to feedback received from one or more manipulator modules by such control system  8 . Further, software may be executing on control system  8  to output (e.g., via a display, printer, audio speakers, and/or other output device included in control system  8 ) information to a user. For instance, information about the positioning of the manipulator modules coupled to platform  10  may be provided to a user via control system  8 . Additionally or alternatively, information about measurements acquired by the manipulator modules in manipulating a sample may be output by control system  8 . That is, in performing manipulation operations on a sample, the manipulator modules may output information to control system  8 , and such control system  8  may output to a user the received information and/or further information derived by such control system  8  from the information received by the manipulator modules. 
     Additionally or alternatively, manipulator modules may, in certain implementations, comprise logic for communicating to control system  8  their individual operative capabilities. For instance, a manipulator module may comprise logic for communicating to control system  8  information about its movement capabilities (e.g., whether it can generate translational movement in one or more of three orthogonal dimensions X, Y, and Z and/or whether it can generate rotational movement). Further, the manipulator module may, in certain implementations, comprise logic for communicating to control system  8  information about its end-effector (e.g., the type of end-effector included in the manipulator module). In certain embodiments, control system  8  may output this information about the operative capabilities of each manipulator module on platform  10  to a user. Further, in certain embodiments, control system  8  may include software that is operable to determine from the operative capabilities of the manipulator module(s) coupled to platform  10  various different types of manipulation operations that are available to a user, given the manipulator module(s) of platform  10 . Thus, for instance, control system  8  may analyze the operative capabilities of the manipulator modules coupled to platform  10  and output the types of manipulation operations that a user may perform with such manipulator modules. In this manner, control system  8  may aid a user in recognizing the types of manipulations (e.g., the types of measurements that may be acquired for a sample and/or the types of assembly operations) that may be performed using the manipulator modules coupled to platform  10 . As described further below, in certain embodiments the manipulator modules are detachably coupled to platform  10  such that a user may selectively configure platform  10  having the manipulator modules desired, and therefore control system  8  may, in certain embodiments, aid a user in recognizing the operative capabilities of any given configuration of platform  10 . 
     In certain embodiments, a manipulator module, such as those described further hereafter in conjunction with  FIG. 4A , may be coupled to an interface site, such as site  1  on platform  10 , in a manner that enables the command signals received at such interface site from control system  8  to be used in controlling the operation of such manipulator module. For instance, a manipulator module may interface with a given site  1 – 4  on platform  10  such that its communication interface (e.g., electrical input and/or output interface) couples with the site&#39;s communication path. For example, a manipulator module may comprise conductive traces for receiving input signals for controlling its operation, and when the manipulator module is coupled to an interface site of platform  10  (e.g., one of sites  1 – 4 ), its conductive traces couple with the appropriate conductive traces that communicatively couple such interface site to control system  8  to enable control system  8  to be used for controlling the operation of the coupled manipulator module. As mentioned above, in certain embodiments, conductive traces of a manipulator module for outputting signals (e.g., measurements, etc.) may be communicatively coupled to the appropriate conductive traces of platform  10  that communicatively couple the manipulator module&#39;s interface site to control system  8 , such that control system  8  can receive signals from such manipulator module. With appropriate addition of motion and displacement sensors for each manipulator module, signals from such sensors can also be routed into control system  8 . Control system  8  may be implemented with proper control software and hardware set up to then monitor the positioning of a manipulator module in real time, and if necessary, calibrate or correct the positioning. In certain implementations, control system  8  may also be coupled with the imaging system provided by the microscope to perform real-time object recognition and positioning identification for controlling positioning of the manipulator module(s) end-effector(s). 
     Thus, in operation, a user may arrange a sample on sample stage  5  (or on one of the manipulator modules) of platform  10 . The user may further selectively couple desired manipulator modules to one or more of the interface sites  1 – 4  of platform  10 . Platform  10  may then be coupled to a microscope in a manner that enables the sample on stage  5  (or, in certain implementations, on one of the manipulator modules coupled to platform  10 ) to be imaged, and the user may utilize control system  8  to controllably manipulate the sample with the selected manipulator module(s) coupled to platform  10 . 
     Preferably, interface  7  enables platform  10  to be detachably coupled to at least one type of microscope for imaging a sample on sample stage  5 . Most preferably, interface  7  enables platform  10  to be detachably coupled at least to SEMs, such as is described more fully hereafter in conjunction with the example of  FIG. 6 . Although, in alternative embodiments, interface  7  may enable platform  10  be coupled to one or more other types of microscopes in addition to or instead of SEMs. Further, interface  7  may, in certain embodiments, be adjustable to enable platform  10  to be detachably coupled to any of a plurality of different types of microscopes. For example, as is described in U.S. patent application Ser. No. 10/173,543, filed on Jun. 17, 2002, and U.S. patent application Ser. No. 10/173,542, concurrently filed on Jun. 17, 2002, entitled “MANIPULATION SYSTEM FOR MANIPULATING A SAMPLE UNDER STUDY WITH A MICROSCOPE,” the disclosures of which have been incorporated herein by reference, may be implemented for platform  10  to enable such platform to adapt to comply with any of a plurality of different microscope interfaces. 
     In view of the above, a preferred embodiment provides a platform  10  that comprises a sample stage  5  and a plurality of interface sites  1 – 4  to enable a selected manipulator module to be coupled thereto. Preferably, such interface sites enable a manipulator module to be detachably coupled thereto such that a user can selectively implement the desired manipulator module(s) on platform  10  for performing a desired type of manipulation on a sample. That is, a user can selectively reconfigure the platform  10  by interchanging various different manipulator modules on the interface sites  1 – 4 . 
     Turning to  FIG. 4A , an example pool  400  of various manipulator modules are shown, which may be selectively coupled to platform  10  (of  FIG. 3 ) in order to configure platform  10  for performing a desired type of manipulation of a sample. In the example pool  400  of  FIG. 4A , block diagrams of manipulator modules  401 ,  402 ,  403 , and  404  are included. Of course, any number of manipulator modules may be included in pool  400  and be available for selection by a user in configuring platform  10  as desired. 
     Preferably, each manipulator module comprises an interface for detachably coupling with an interface site (e.g., one of sites  1 – 4 ) of platform  10 . For example, manipulator modules  401 – 404  comprise interfaces  401 B,  402 B,  403 B, and  404 B, respectively. Such interfaces  401 B,  402 B,  403 B, and  404 B preferably comply with the interface sites  1 – 4  of platform  10  to enable any of manipulator modules  401 – 404  to be coupled to any of interface sites  1 – 4 . The interface of a manipulator module (e.g., interface  401 B of manipulator module  401 ) serves for mechanically fixing and electrically connecting the manipulator module to platform  10  via one of interface sites  1 – 4 , so as the keep the integrity of each manipulator module. Interface sites  1 – 4  are so designed on platform  10  to fit the dimension requirement of the microscope(s) with which platform  10  is intended to be used, and each interface site  1 – 4  preferably includes mechanical and electrical connectors for operatively coupling a manipulator module to platform  10 . 
     In one example implementation, approximately  10  electrical traces are available in each of interface sites  104 , and when mechanically coupled therewith, a manipulator module may form an electrical connection with one or more of such electrical traces to communicatively couple with control system  8 . For instance, certain manipulator modules may couple with a first number (e.g.,  5 ) of the available electrical traces of an interface site to enable communication of control signals from control system  8  to such manipulator modules and/or output information from such manipulator modules to control system  8 , and certain other manipulator modules may couple with a different number (e.g.,  10 ) of the available electrical traces to enable an increased (or decreased) amount of control signals and/or output information to be communicated between control system  8  and the manipulator modules. For instance, certain manipulator modules may couple with a first number (e.g.,  5 ) of the available electrical traces of an interface site to enable communication of control signals from control system  8  to such manipulator modules and/or output information from such manipulator modules to control system  8 , and certain other manipulator modules may couple with a different number (e.g.,  10 ) of the available electrical traces to enable an increased (or decreased) amount of control signals and/or output information to be communicated between control system  8  and the manipulator modules. 
     In a preferred embodiment, such as that described in conjunction with  FIG. 5  below, each of interface sites  1 – 4  of platform  10  are approximately 15 mm by 15 mm in size (thus enabling a platform  10  that is suitable for interfacing with the sample chamber of an SEM). Of course, in alternative embodiments interface sites  1 – 4  may each have sizes other than 15 mm by 15 mm to enable platform  10  to be of appropriate size for interfacing with a desired microscope. For instance, a platform  10  that is configured to interface with a TEM&#39;s sample chamber, for example, may comprise interface sites that are smaller than 15 mm by 15 mm for receiving a manipulator module. 
     Each manipulator module of pool  400  preferably comprises an end-effector for manipulating a sample. For example, manipulator modules  401 – 404  comprise end-effectors (EE)  401 C,  402 C,  403 C, and  404 C, respectively. Such end-effectors may be utilized to engage and/or otherwise manipulate a sample arranged on sample stage  5  of platform  10 . Examples of end-effectors that may be utilized are described further hereafter in conjunction with  FIG. 4B . In certain implementations, the manipulator modules may comprise an interface for receiving any of a plurality of different types of end-effectors. For example, manipulator modules  401 – 404  comprise end-effector interfaces  401 D,  402 D,  403 D, and  404 D, respectively. Thus, in certain implementations, a manipulator module may have an interface (such as interfaces  401 D,  402 D,  403 D, and  404 D) that enables a user to detachably couple any of a plurality of different types of end-effectors to such manipulator module, such that a user may selectively configure the manipulator module to include a desired type of end-effector. 
     Further, each manipulator module preferably comprises a drive mechanism for controllably imparting movement to the manipulator module&#39;s end-effector. For example, an actuation mechanism for imparting translational movement and/or rotational movement to an end-effector may be included within a manipulator module. For example, manipulator modules  401 – 404  comprise drive mechanisms  401 A,  402 A,  403 A, and  404 A, respectively. More specifically, in the example of  FIG. 4A , manipulator module  401  comprises a drive mechanism  401 A that is operable to provide three degrees of translational movement (along three orthogonal axes X, Y, and Z) of end-effector  401 C. Manipulator module  402  comprises a drive mechanism  402 A that is operable to provide three degrees of translational movement (along three orthogonal axes X, Y, and Z), as well as rotational movement of end-effector  402 C. Manipulator module  403  comprises a drive mechanism  403 A that is operable to provide two degrees of translational movement (along two orthogonal axes X and Y) of end-effector  403 C. Manipulator module  404  comprises a drive mechanism  404 A that is operable to provide two degrees of translational movement (along two orthogonal axes X and Y), as well as rotational movement of end-effector  404 C. 
     In certain embodiments, a manipulator module may comprise a first drive mechanism that enables relatively large, coarse movement of an end-effector, and the manipulator module may further comprise a second drive mechanism that enables relatively fine, precise movement of an end-effector. Accordingly, the first drive mechanism may be used to perform relatively coarse adjustment of the positioning of the manipulation module&#39;s end-effector relative to a sample on sample stage  5 , and the second drive mechanism may be used for performing more fine/precise positioning of such end-effector. For instance, drive mechanism  401 A of manipulator module  401  may comprise a first drive mechanism that provides relatively large, coarse X, Y, and Z movement of end-effector  401 C, and drive mechanism  401 A may further comprise a second drive mechanism  401 E (shown in dashed line in  FIG. 4A  as being optional) that provides relatively fine, precise movement of end-effector  401 C. Such second drive mechanism  401 E may provide translational movement of end-effector  401 C in one or more dimensions (e.g., X, Y, and/or Z movement) and/or rotational movement of end-effector  401 C. Similar to manipulator module  401 , manipulator modules  402 – 404  may each comprise a first drive mechanism for providing relatively large, coarse movement of their respective end-effectors, and a second drive mechanism  402 E,  403 E, and  404 E, respectively, for providing relatively fine, precise movement of their respective end-effectors. 
     Thus, in a preferred embodiment, a manipulator module&#39;s drive mechanism may comprise a first drive mechanism that provides a relatively large range of movement for the module&#39;s end-effector (but may have less precision than the second drive mechanism) and a second drive mechanism that provides a relatively fine range of movement with great precision. For example, in one implementation of a preferred embodiment, a microactuator that provides a relatively large travel distance is implemented. For instance, a linear stepper microactuator may be implemented to provide such a large travel range for a manipulator module&#39;s end-effector. Linear stepper microactuators are well-known in the art, and therefore are not described in greater detail herein. In alternative implementations, any of various other suitable microactuators now known or later developed may be implemented within a manipulator module to provide a relatively large travel range for the module&#39;s end-effector, including without limitation a stick-slick piezoelectric actuator, an ultrasonic piezoelectric actuator, or an inchworm piezoelectric actuator, all of which are well-known in the art. 
     In one implementation of a preferred embodiment, a linear stepper microactuator is implemented in the first drive mechanism of a manipulator module and provides a translation range of several millimeters to the module&#39;s end-effector with a step resolution of approximately 30 nanometers. Thus, such a first drive mechanism may be utilized to move the module&#39;s end-effector in one or more dimensions (e.g., in the example of module  401 , it provides such movement in three dimensions X, Y, and Z). More specifically, the first drive mechanism may comprise a plurality of such linear stepper microactuators to enable independent (or decoupled) movement of the manipulator module&#39;s end-effector in a plurality of dimensions. For instance, a first linear stepper microactuator may be implemented to impart movement to the end-effector in one dimension (e.g., along an X axis); a second linear stepper microactuator may be implemented to impart movement to the end-effector in an orthogonal dimension (e.g., along a Y axis); and a third linear stepper microactuator may be implemented to impart movement to the end-effector in a third orthogonal dimension (e.g., along a Z axis). The precision of positioning the end-effector using such linear stepper microactuators is generally limited by the resolution of the microactuator&#39;s step (i.e., the distance of each step). In the example implementation described above, the step resolution of the linear stepper microactuators used is approximately 30 nanometers, and therefore such microactuators of a manipulator module&#39;s first drive mechanism may be used to position the module&#39;s end-effector to within approximately 30 nanometers of a desired position. 
     Further, in a preferred embodiment, a manipulator module&#39;s drive mechanism may comprise a second drive mechanism that provides a relatively fine range of movement with great precision. For example, in one implementation of a preferred embodiment, a microactuator that provides very precise movement is implemented. For instance, a piezo tube may be implemented to provide such precise movement of a manipulator module&#39;s end-effector. For instance, a quadruple electroded piezoelectric tube may be implemented to provide such precise movement of a manipulator module&#39;s end-effector in free space in the range of a few microns with sub-nanometer resolution. Such quadruple electroded piezoelectric tubes are well-known in the art, and therefore are not described in greater detail herein. Alternatively, such well-known actuators as a piezostack, a piezo bimorph, or a simple piezo plate, as examples, may be used if such fine translation of the module&#39;s end-effector is needed in only one dimension. 
     In one implementation of a preferred embodiment, a quadruple electroded piezoelectric tube is implemented in the second drive mechanism of a manipulator module and provides a translation range of several micrometers to the module&#39;s end-effector with resolution of approximately 1 nanometer (or less). Thus, such a second drive mechanism may be utilized to move the module&#39;s end-effector in one or more dimensions (e.g., it may provide such movement in three dimensions X, Y, and Z) a relative small distance (e.g., up to several micrometers) with great precision (e.g., approximately 1 nanometer precision). Accordingly, such second drive mechanism of a manipulator module may be utilized to perform very precise positioning of the module&#39;s end-effector in order to perform desired manipulation of a sample. 
     In certain embodiments, a manipulator module may comprise only a single drive mechanism, such as a drive mechanism that enables relatively fine, precise movement of an end-effector (e.g., drive mechanism  401 E,  402 E,  403 E, and  404 E). For instance, such a single drive mechanism for a manipulator module may comprise a quadruple electroded piezoelectric tube that provides a translation range of several micrometers to the module&#39;s end-effector with resolution of approximately 1 nanometer (or less). Having a single drive mechanism may be beneficial in certain embodiments in that it may enable the modular manipulation system to be configured for use with a microscope that has a relatively limited sample chamber, such as the sample chamber of commercially available TEMs. For instance, as is described in U.S. patent application Ser. No. 10/173,543, filed on Jun. 17, 2002, and U.S. patent application Ser. No. 10/173,542, concurrently filed on Jun. 17, 2002, entitled “MANIPULATION SYSTEM FOR MANIPULATING A SAMPLE UNDER STUDY WITH A MICROSCOPE,” the disclosures of which have been incorporated herein by reference, by including only a high-precision actuator for each manipulator mechanism within the manipulation system (or “sample holder”), such manipulation system may be capable of having a plurality of manipulator mechanisms arranged therein and still be of suitable size for interfacing with a relatively limited sample chamber, such as the sample chamber of commercially available TEMs. As further described in “MANIPULATION SYSTEM FOR MANIPULATING A SAMPLE UNDER STUDY WITH A MICROSCOPE”, a coarse adjustment mechanism that is independent from the manipulation system (or “sample holder”) may be utilized in certain implementations to engage the manipulator mechanisms coupled to platform  10  and provide relatively long-range, coarse movement to their end-effectors in order to initially position such end-effectors, and thereafter, the internal actuator associated with each manipulator mechanism may be used to perform high-precision movement thereof (e.g., for manipulating a sample under study). 
     Turning now to  FIG. 4B , examples of end-effectors that may be implemented on a manipulator module are shown. More specifically, an example pool  450  of various end-effectors are shown. In certain embodiments, such end-effectors may be selectively coupled to any of a plurality of different manipulator modules (such as the manipulator modules of pool  400  in  FIG. 4A ) in order to configure a manipulator module as desired for performing manipulation of a sample. In the example pool  450  of  FIG. 4B , example end-effectors  451 ,  452 ,  453 ,  454 , and  455  are included. Of course, any number of end-effectors may be included in pool  450  and be available for selection by a user in configuring a manipulator module as desired. In this example, end-effector  451  comprises a probe, end-effector  452  comprises a glass fiber, end-effector  453  comprises a gripper, end-effector  454  comprises a hypodermic needle, and end-effector  455  comprises a hose. Such end-effectors  451 – 455  may be utilized to engage and/or otherwise manipulate a sample arranged on sample stage  5  of platform  10 . Various other types of end-effectors now known or later developed may be included in pool  450  in addition to or instead of the example end-effectors shown in  FIG. 4B . 
     In certain implementations, a manipulator module may comprise an interface for receiving any of the various different end-effectors of pool  450 . For example, manipulator modules  401 – 404  of  FIG. 4A  comprise end-effector interfaces  401 D,  402 D,  403 D, and  404 D, respectively. Thus, in certain implementations, a manipulator module may have an interface (such as interfaces  401 D,  402 D,  403 D, and  404 D) that enables a user to detachably couple any of the end-effectors of pool  450  to such manipulator, such that a user may selectively configure the manipulator module to include a desired type of end-effector. 
       FIG. 5  shows an example implementation of a preferred embodiment of a manipulation platform  500 . In this example implementation, manipulation platform  500  includes base  6  on which a plurality of manipulator module interface sites are arranged, such as sites  1 ,  2 ,  3 , and  4  of  FIG. 3 . In this example, a manipulator module is coupled to each of the base&#39;s interface sites. Thus, manipulator modules  501 ,  502 ,  503 , and  504  are coupled to base  6 . Preferably, such manipulator modules  501 – 504  are detachably coupled to base  6  such that a user may remove each module and replace it with a different module (such as a module selected from pool  400  of  FIG. 4A ). While four manipulator modules are shown as coupled to base  6  in the example configuration of  FIG. 5 , it should be understood that in alternative implementations a different number of such manipulator modules (either fewer than or greater than 4) may be so coupled to base  6 . As described above, it is most preferable for base  6  to include at least four manipulator module interface sites (such as sites  1 – 4  shown in the example of  FIG. 3 ), but depending on the type of manipulation desired by a user, a manipulator module need not be coupled to each interface site available on base  6 . 
     Platform  500  comprises a sample stage  5  for receiving a sample to be studied using a microscope. Thus, manipulator modules  501 – 504  are arranged about such sample stage  5  and may be used to perform manipulation of a sample arranged on sample stage  5 . Platform  500  further comprises an interface  7  that enables base  6  to be coupled to a microscope such that a sample arranged on sample stage  5  can be imaged by such microscope. Most preferably, interface  7  enables base  6  to be coupled at least to an SEM. Once platform  500  is coupled to a microscope, a sample arranged on sample stage  5  may be imaged as manipulator module(s)  501 – 504  are utilized to manipulate the sample. As further shown in  FIG. 5 , control system  8  may be coupled to platform  500  to enable a user to control the operation of manipulator modules  501 – 504  in order to manipulate a sample in the manner desired. 
     In this example, manipulator module  501  comprises a first drive mechanism that includes linear stepper microactuators  501 A,  501 B, and  501 C. Manipulator module  501  further comprises a second drive mechanism that includes piezoelectric tube  501 D. Manipulator module  501  further comprises an end-effector  501 F that is coupled to piezoelectric tube  501 D via interface  501 E. As shown, in this example, piezoelectric tube  501 D of the second drive mechanism is coupled to the first drive mechanism (comprising linear stepper microactuators  501 A– 501 C) such that the first drive mechanism is operable to move piezoelectric tube  501 D (as well as end-effector  501 F coupled to such piezoelectric tube  501 D). More specifically, linear stepper microactuator  501 A is operable to impart movement to piezoelectric tube  501 D (and, in turn, end-effector  501 F) along the X axis shown. Linear stepper microactuator  501 B is operable to impart movement to piezoelectric tube  501 D (and, in turn, end-effector  501 F) along the Y axis shown, and linear stepper microactuator  501 C is operable to impart movement to piezoelectric tube  501 D (and, in turn, end-effector  501 F) along the Z axis shown. Thus, manipulator module  501  is an example module that provides translation of end-effector  501 F in three orthogonal dimensions (X, Y, and Z), such as with manipulator module  401  of  FIG. 4A . 
     Linear stepper microactuators  501 A– 501 C may each provide a relatively large travel range. For instance, each of linear stepper microactuators  501 A– 501 C may provide a translation range of several millimeters. Thus, the first drive mechanism of manipulator module  501  may be controllably operable to move end-effector  501 F up to several millimeters along the X, Y, and/or Z axes. The precision of positioning end-effector  501 F using such linear stepper microactuators  501 A– 501 C is generally limited by the resolution of the microactuator&#39;s step (i.e., the distance of each step). In this example implementation, the step resolution of linear stepper microactuators  501 A– 501 C is approximately 30 nanometers, and therefore such microactuators may be used to position end-effector  501 F to within approximately 30 nanometers of a desired position. 
     Further, in this example implementation, manipulator module  501  comprises a second drive mechanism that provides a relatively fine range of movement with great precision. More specifically, piezoelectric tube  501 D is implemented as such a second drive mechanism to provide precise movement of end-effector  501 F. In this example, piezoelectric tube  501 D provides a translation range of several micrometers to end-effector  501 F with resolution of approximately 1 nanometer. Such piezoelectric tube  501 D may be utilized to move end-effector  501 F in one or more dimensions (e.g., it may provide movement in three dimensions X, Y, and Z) a relatively small distance (e.g., up to several micrometers) with great precision (e.g., approximately 1 nanometer precision). Accordingly, such piezoelectric tube  501 D may be utilized to controllably perform very precise positioning of end-effector  501 F in order to perform desired manipulation of a sample arranged on sample stage  5 . 
     In the example of  FIG. 5 , manipulator modules  502  and  503  are identical to module  501  described above. Thus, each of manipulator modules  502  and  503  includes a first drive mechanism that comprises three linear stepper microactuators for imparting a relatively long range of movement to the module&#39;s respective end-effector, and each of such manipulator modules  502  and  503  includes a second drive mechanism that comprises a piezoelectric tube for performing very precise positioning of the module&#39;s respective end-effector. 
     However, manipulator module  504  is different than manipulator modules  501 – 503 . That is, in this example, a user has selectively coupled three identical manipulator modules  501 – 503  to platform  500 , and has selectively coupled a different type of manipulator module  504  (which provides different operational capabilities) to platform  500 . Similar to manipulator modules  501 – 503 , manipulator module  504  comprises a first drive mechanism that includes linear stepper microactuators  504 A,  504 B, and  504 C that are operable to provide relatively long range movement to the module&#39;s end-effector along the X, Y, and Z axes, respectively. Also similar to manipulator modules  501 – 503 , manipulator module  504  further comprises a second drive mechanism that includes piezoelectric tube  504 E that is operable to provide relatively fine, precise movement to the module&#39;s end-effector (e.g., in three dimensions X, Y, and Z). In addition, the first drive mechanism of manipulator module  504  further comprises a microactuator  504 D that is operable to impart rotational movement to the module&#39;s end-effector. Preferably, microactuator  504 D comprises a stick-slip type piezoelectric rotational actuator that can be operated in continuous  360  degree rotation and has an angular step resolution of less than 0.02 degree. Thus, manipulator module  504  is an example module that provides translation of its end-effector in three orthogonal dimensions (X, Y, and Z), as well as providing rotational movement of such end-effector, such as with manipulator module  402  of  FIG. 4A . 
     Preferably, each of modules  501 – 504  are detachably coupled to base  6 , such that a user may remove any one or more of such modules, and, if so desired, may replace the module with a different module (e.g., selected from pool  400  of  FIG. 4A ). Accordingly, it should be understood that by arranging the desired types of modules on the appropriate interface sites of base  6 , a user may selectively configure platform  500  as desired for performing manipulation on a sample. Thus, in operation, a user may arrange a sample on sample stage  5  of platform  500 . The user may further selectively couple desired manipulator modules, such as modules  501 – 504  shown in the example of  FIG. 5 , to one or more of the interface sites of platform  500 . Platform  500  may then be coupled to a microscope in a manner that enables the sample on stage  5  to be imaged, and the user may utilize control system  8  to controllably manipulate the sample with the selected manipulator module(s) coupled to such platform  500 . 
     Preferably, interface  7  enables platform  500  to be detachably coupled to at least one type of microscope for imaging a sample on sample stage  5 . Most preferably, interface  7  enables platform  500  to be detachably coupled at least to SEMs. For instance, in the example implementation of  FIG. 5 , base  6  comprises a length “L” of approximately 10 cm, and a width “W” of approximately 10 cm. Further, in the example implementation of  FIG. 5 , platform  500  comprises an overall height “H” of approximately 4 cm. Such an implementation of platform  500  is capable of being detachably coupled at least with most commercially available SEMs (e.g., to their sample chamber) to enable manipulation of a sample arranged on sample stage  5  while such sample is being imaged by the SEM. Of course, in alternative embodiments, platform  500  may be implemented having different dimensions such that it is suitable for being detachably coupled with other types of microscopes in addition to or instead of SEMs in a manner that enables a sample on stage  5  to be imaged while it is being manipulated with one or more manipulator modules of platform  500 . 
       FIG. 6  shows an example implementation of a manipulation platform of a preferred embodiment coupled with an SEM. More specifically,  FIG. 6  shows platform  500  of  FIG. 5  (in block diagram form) coupled with an SEM, such as the example SEM shown in block diagram  200 A of  FIG. 2 . As shown, platform  500  is coupled with the SEM&#39;s sample chamber  214  such that a sample arranged on sample stage  5  may be imaged by the SEM. Further, while such sample is being imaged by the SEM, modules  501 – 504  may be controllably utilized to manipulate the sample in a desired manner. 
     In view of the above, a preferred embodiment provides a platform  10  that comprises a sample stage  5  and a plurality of interface sites  1 – 4  to enable a selected manipulator module to be coupled thereto. Preferably, such interface sites enable a manipulator module to be detachably coupled thereto such that a user can selectively implement the desired manipulator module(s) on platform  10  for performing a desired type of manipulation on a sample. That is, a user can selectively reconfigure the platform  10  by interchanging various different manipulator modules on the interface sites  1 – 4 . 
     Turning now to  FIG. 7 , an operational flow diagram is shown that illustrates an example of how certain embodiments of the present invention may be utilized. More specifically,  FIG. 7  shows an example operational flow diagram for configuring a manipulator platform (such as the example platform  500  of  FIG. 5 ) and using such manipulator platform with a microscope to study a sample. As shown, in operational block  701  a user selects at least one manipulator module to use in manipulating a sample. For example, a user may select one or more desired types of manipulator modules from a pool of such modules (e.g., pool  400  of  FIG. 4A ). As further shown in  FIG. 7 , in selecting a desired type of manipulator module, a user may, in operational block  701 A, select a desired type of end-effector to be coupled to such manipulator module. That is, in certain embodiments, a manipulator module may comprise an interface that enables any of a plurality of different types of end-effectors, such as the end-effectors of pool  450  of  FIG. 4B , to be detachably coupled to such manipulator module. Accordingly, in operational block  701 A a user may select a desired type of end-effector, and in operational block  701 B, a user may couple the selected end-effector to a selected manipulator module. Of course, in certain embodiments, a manipulator module may already comprise a desired end-effector coupled thereto and/or a manipulator module may not comprise an interface that enables an end-effector to be detachably coupled therewith (e.g., the manipulator module may comprise a “fixed” end-effector). Thus, operational blocks  701 A and  701 B are shown in dashed line as being optional. 
     In operational block  702 , the manipulator module(s) selected in block  701  are each coupled to an interface site of a manipulator platform, such as interface sites  1 – 4  of manipulator platform  10  of  FIG. 3 . Thus, by coupling the desired manipulator modules to a manipulator platform, the user configures the manipulator platform as desired (e.g., to perform a desired type of manipulation of a sample). In block  704 , a user arranges a sample on a sample stage of the manipulator platform, such as on sample stage  5  of manipulator platform  10  shown in  FIG. 3 . In operational block  704 , the manipulator platform is interfaced with a microscope, such as an SEM, such that the sample can be imaged by the microscope. Thereafter, in operational block  705 , the selected manipulator modules coupled to the manipulator platform are used to manipulate the sample, preferably while such sample is being imaged by the microscope. 
     As described above, manipulation platform  10  preferably comprises a plurality of interface sites, each for receiving a manipulation module. Most preferably, at least four manipulation modules may be implemented within such manipulation platform  10 . Having a plurality of manipulation modules enables various types of measurements to be acquired for a sample under study. Certain embodiments of the present invention enable measurements that have traditionally been unavailable because of an insufficient number of manipulation mechanisms being implemented for a microscope&#39;s manipulation system. 
     For example, with conductive and sharp probes, such as etched conductive W, Pt, Au probes, implemented as an end-effector, conductivity measurement can be performed on a nanometer-scale section of a sample either placed on the surface of sample stage  5  or suspended in free space by positioning two probes on the surface of the sample (i.e., using two probes to hold the sample in free space and one or more other probes to acquire measurements of sample). With 4 manipulator modules on one platform, a four-probe kelvin conductivity measurement can be conducted down to the nanometer-scale on samples under study. One advantage of a four-probe conductivity measurement is that the contact resistance effect intrinsic to the formed interface between the probe and the sample can be neutralized, and the exact conductance of the sample can be obtained, which is not possible for two or three probe conductivity measurement. A multi-module manipulator design also facilitates the ready prototyping of devices inside the microscope. For example, a three-probe manipulator (e.g., manipulation platform  10  comprising 3 manipulator modules) can implement a field effect transistor measurement utilizing the third probe to apply a gate voltage while measuring the “IV” (current, voltage) characteristic of the sample from the other two probes. With use of other types of end-effectors, such as force probes, force measurement or combined force/electrical measurement can also be realized down to the nanometer-scale. As those of skill in the art will appreciate, embodiments of the present invention enable various other types of measurements and/or characterizations to be acquired for a sample. 
     Further, the manipulation system of certain embodiments of the present invention may be utilized to perform assembly operations on micro- and/or nano-scale objects. For example, a plurality of samples may be arranged on stage  5 , and manipulation modules (such as modules  501 – 504  of  FIG. 5 ) may, in certain applications, be used to assemble such samples into a desired structure. Additionally, various other applications of such a manipulation system will be recognized by those of ordinary skill in the art. 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.