DESC:TECHNICAL FIELD
The present disclosure relates to the field of Scanning Probe Microscopy. More specifically, but not exclusively, the present disclosure relates to a probe for high speed atomic force microscopy.

BACKGROUND
The Atomic Force Microscopy (AFM) has emerged as a remarkable imaging tool in nanotechnology and has been applied in the study of several dynamic processes at nanoscale. It uses a micro-cantilever probe with an atomically sharp tip to apply forces on a surface of a sample, for analysing the sample as seen in Figure:1. The slow speed of operation of the conventional AFM system limits the set of processes that can be examined, resulting in poor temporal resolution of captured image which makes it disadvantageous to be used for time based changes occurring on a sample, particularly if it is a biological sample. is the only viable characterization technique of the kind for characterizing biological samples, and the reduction in frequency of the probe’s movement in fluidic environment during scanning of biological sample due to damping effect of the fluidic environment further credits the need for a high speed AFMs.

Traditional systems like piezo positioners are used to increase speed of imaging. Piezo positioners move the sample surface or the probe, up/down in accordance with the mechanical stress induced on the probe while it bends during the scan when passed over a ridge or trough on the sample surface. However, piezo actuators possess several significant drawbacks such as creep and hysteresis. Further, traditionally, depending on the sample to be scanned, a controller is programmed to scan with higher frequency, if the changes in the topology of the sample is assumed to be more per unit area. Further, the controller of the atomic microscopy system is programmed to scan at higher range and thereby lower frequency, if the topology of the sample surface is assumed to comprise deeper troughs or high ridges. There is no setting of the AFM where it can be used to scan universally for any sample on the scan surface.

Use of actuators to enhance the speed of an AFM is another viable option. Integrated piezo-electric actuators used in conventional high speed AFMs limit the bandwidth of the probe. The bandwidth of the probe can be described as the number of data samples collected over a period of time and is proportional to the frequency of the probe.

Further, the use of flexural deformation of the AFM probe along its central axis to actuate the probe also results in a trade-off between range and resonant frequency. Thus, the probe can either comprise higher range of flexural movement and thus operate at a lower frequency, which is not ideal for high speed scanning and comprise lower range of flexural movement and thus operate at a higher frequency, which would compromise the use of probe on samples with deeper attributes.

The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

BRIEF DESCRIPTION OF THE ACCOMPANYING DIAGRAMS

The novel features and characteristic of the disclosure are set forth in the appended description. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

Figure 1 shows an exemplified embodiment of an existing AFM probe positioned over a scanning surface;

Figure 2 shows lateral view of an magnetically actuated active probe 100 in accordance with some embodiments of the present disclosure;

Figure 3 shows zoomed-in view of the magnetically actuated active probe 100 depicting one or more compliant members and support member in accordance with some embodiments of the present disclosure;

Figure 4 shows the depiction of magnetic actuator placed in the vicinity of the probe in accordance with some embodiments of the present disclosure;

Figure 5 shows an exemplary architecture of an Atomic force microscopy system 500 in accordance with some embodiments of the present disclosure;

Figure 6 shows a block diagram of an Atomic force microscopy system 500 in accordance with some embodiments of the present disclosure; and

Figure 7 shows a flowchart illustrating a method of fabrication of magnetically actuated active probe 100 in accordance with some embodiments of the present disclosure;

Figure: 8 shows the fabricated actuator in in accordance with some embodiments of the present disclosure

The Figures and the following description relate to various embodiments by way of illustration only. It should be noted that from the following discussion, alternative embodiments of the structures disclosed herein will be readily recognized as viable alternatives that may be employed without departing from the principles discussed herein. Reference will now be made in detail to several embodiments, examples of which are illustrated in the accompanying figures. It is noted that wherever practicable similar or like reference numbers may be used in the figures and may indicate similar or like functionality.

SUMMARY
Disclosed herein is an magnetically actuated active probe, the atomic microscopy system and a method of fabrication of the magnetically actuated magnetically actuated active probe. The magnetically actuated magnetically actuated active probe comprises a base member. The magnetically actuated magnetically actuated active probe comprises a lever, wherein one end of the lever comprises the base member and the other end is defined with a tip . One or more of magnets fixed on the base member, wherein the lever is positioned perpendicular to axis passing through the cross-sectional center of mass the one or more of magnet. One or more compliant elements disposed between the one or more of magnets. The one or more compliant elementsare defined in gaps between each of the one or more of magnets and a support member. The magnetically actuated active probe is connected to the atomic force microscope unit through the support member. The magnetically actuated active probe is configured to traverse a scan surface for scanning at high speed.

Further the present disclosure discloses an atomic microscopy system. The atomic microscopy system comprises a magnetically actuated active probe, an actuator, optical element, a detector, a processor and a memory. The memory is communicatively coupled to the processor, wherein the processor is configured to receive information related to displacement of the lever , from the detector and generate an image of a scan surface by the magnetically actuated active probe using the information related to displacement of the lever.

Further, the present disclosure discloses a fabrication method for magnetically actuated active probe. The method comprises attaching a unmagnetized magnet particle to a probe, wherein the unmagnetized magnet particle is closer to a base of the probe. Further, the method comprises machining using a machining tool, the unmagnetized magnet particle to form at least, one or more magnets and one or more compliant elements201 between the one or more magnets. The method further comprises machining the probe to have a lever of length 300-700µm and width 30-70 µm with a tip 105 having dimensions 3-18 µm using plurality of current settings for machining.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

For a better understanding of exemplary embodiments of the present invention, together with other and further features and advantages thereof, reference is made to the following description, taken in conjunction with the accompanying drawings

DETAILED DESCRIPTION

In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the disclosure.

The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a device or system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the device or system or method.

The present disclosure relates to a magnetically actuated active probe and an Atomic force microscopy system. The Atomic force microscopy system may comprise a magnetically actuated active probe, wherein the magnetically actuated active probe may comprise, a base member, a lever where one end of the lever is connected to the base member and the other end is defined with a tip. One or more of magnets may be fixed on the base member, where the lever is positioned perpendicular to axis passing through the cross-sectional center of mass of the one or more of magnets. One or more compliant element may be disposed between the one or more of magnets and one or more compliant elements may be defined in gaps between each of the one or more of magnets and a support member. The magnetically actuated active probe is connected to the atomic force microscope unit through the support member and the magnetically actuated active probe is configured to traverse a scan surface for scanning at high speed. An actuator comprising at least a current carrying wire may be placed in the vicinity of the one or more magnets to generate a magnetic field for actuating the magnetically actuated active probe is configured to evenly distribute the magnetic field around the one or more magnets. An optical element may be configured to project an optical beam on a reflector of the magnetically actuated active probe and a detector may be configured to receive and process the reflected optical beam from the reflector to detect displacement of the lever. A processor in the atomic microscopy system may be communicatively coupled to the memory. The Atomic force microscopy system processor may receive information related to displacement of the lever from the detector and further generate an image of a sample on scan surface by the magnetically actuated active probe using the information related to displacement of the lever with respect to its normal resting state. In this manner the present disclosure uses the magnetically actuated active probe to scan a scan surface at high speed.

Figure 2 Shows lateral view of an magnetically actuated active probe 100 in accordance with some embodiments of the present disclosure.

The magnetically actuated active probe 100 may comprise a base member 101, a lever 102, where one end of the lever 102 comprises the base member 101 and the other end is defined with a tip 105. The geometry of the lever 102 is designed in a manner to increase the resonance frequency of the lever 102. For example, the cross-sectional area of the lever 102 ranges from _________and in another example, the length of the lever 102 is in the range of 80-100µm. As an example, if the resonance or eigen frequency of the lever 102 is more, the speed with which the probe can move is directly influenced and thus, the number of samples collected from the scan surface, termed as the bandwidth of the probe is increased. In some of the embodiments of the present disclosure, the resonance frequency of the magnetically actuated active probe 100 is 100-500KHz. A person skilled in the art will appreciate the fact that the resonance frequency of the magnetically actuated active probe 100 may vary based on application and the dimensions of the lever 102 102 and is not limited to the range of 100-500KHz. Further in an exemplified embodiment, the lever 102 is a rigid structure, which does not bend during the scanning process, thus the range of linear displacement of the lever 102 is increased. In an exemplified embodiment the lever 102 is linearly displaced in a range of 250nm to 1 µm. In another exemplified embodiment the range of linear displacement of lever 102 is independent of the resonance frequency of the lever 102. In another embodiment, the magnetically actuated active probe 100 further comprises a reflector 106 positioned on the lever 102 to enable detection of the linear displacement of the lever 102. In an exemplified embodiment, the reflector 106 is placed in a manner, towards the base member 101 to reduce the influence of inertia and drag exerted by the reflector 106 on the resonance frequency of the lever 102. As an example, the probe can scan at higher resonance frequency with higher range, which means, it is capable of scanning any samples with deeper troughs or high ridges at same high speed, without compromising the bandwidth or number of samples collected.

One or more of magnets 103 of the magnetically actuated active probe 100 are fixed on the base member 101 wherein the lever 102 is positioned perpendicular to an axis passing through the cross-sectional center of the one or more of magnets. In an exemplified embodiment, the magnetic moment of the magnetic particle ranges from 7 x 10-9Am2__to _11 x 10-9Am2.. In an exemplified embodiment, the one or more magnets 103 may comprise an alloy comprising at least two of neodymium, iron and boron. The one or more magnets 103 are actuated by an actuator 301 comprising at least a current carrying wire.

Figure 3 shows zoomed-in view of the magnetically actuated active probe 100 depicting one or more compliant members 104 and support member 104 201 in accordance with some embodiments of the present disclosure;

The one or more compliant elements201 are disposed between the one or more of magnets 103. The one or more compliant elements201 are defined in gaps between each of the one or more of magnets and a support member 104. The magnetically actuated active probe 100 is connected to the atomic force microscope unit through the support member 104 wherein the magnetically actuated active probe 100 is configured to traverse a scan surface for scanning at high speed. In an exemplified embodiment of the present disclosure, the atomic force microscope unit comprise an AFM instrument. In an exemplified embodiment, the one or more of magnets, one or more compliant elements201 and the support member 104 are made from a single unmagnetized magnet particle. In another embodiment, plurality of particles in different sizes may be attached serially to comprise same orientation and the required magnetic moment. In an exemplified embodiment, the probe is fabricated by NCLR silicon probes (Non-contact/tapping mode long cantilever 102 NCLR) with Al coating of 10 nm, nano sensors. The one or more magnetic particle is selected from a magnetic powder with particles of naturally elongated geometry. An un-magnetized particle from the magnetic powder is selected and the particle is attached close to the base using adhesive (Standard Epoxy Adhesive, Araldite). The particle is attached at a short distance away from the base.

As an example, the compliant elements are structured in a manner that when a magnetic field is applied around/ in vicinity of the magnetically actuated active probe 100one or more magnets 103, the one or more magnets 103 exerts a torsional stress on the one or more compliant elements201. The one or more compliant elements201 acts as a spring due to the torsional stress thus pulling the lever 102 in a manner that the lever 102 is linearly displaced from the scan surface. Upon removal of the magnetic field, an inertia is exerted by the one or more magnets 103 on the lever 102, therefore bringing the lever 102 of the probe towards the surface.

In an exemplified embodiment, the probe was machined by using Focused Ion Beam milling. The magnetic particle and the probe were machined from above. In an exemplified embodiment, the width and length of the probe is machine to be close to 30-70 µm and 300-700 µm respectively. The features were coarsely machined at high ion current of 9.3 nA and subsequently finely machined at 0.79 nA to reduce the dimensions to their desired dimensions. Subsequently, the particle was machined from the front to reduce its thickness to its final dimensions.

As an example, the lumped parameter model may be used to optimize the design of the magnetically actuated active probe 100. If K? represents the torsional stiffness of the one or more compliant elements201, the applied magnetics torque ? results in a quasi-static displacement Z of the one or more compliant elements201 given by Z = -?l / K? , where l represents the length of the lever 102. Thus, for a maximum applicable field B0, the quasi-static displacement range Z0 is given by equation (1) below,

The one or more compliant elements201 twist in response to both the tip 105-sample force Fts and the applied magnetics torque ?. The dynamics of the probe is governed by the Equation (2) below:

From Equation (2) the linear stiffness kz of the probe is given by Equation (3) below

while its eigen-frequency f0 is given by Equation (4) below

For the one or more compliant element with cross sectional width, thickness and length wn, hn and ln respectively, the stiffness for torsional deformation about X-axis is given by equation (5) below,

where, wn ? hn , the constant ? is a function of wn / hn and G is the shear modulus of the material of the one or more compliant elements201. Likewise, the overall mass moment of inertia I of the probe about the axis of the rotation is the sum of those due to the particle (Ip), lever 102 ( Ilever 102 ), reflector 106 ( Iref ) and the tip 105 ( Itip 105 ), and given by equation (6) below,

For a magnet particle of width, length and thickness wp, lp , and hp respectively, a lever 102 of uniform cross-section Ac, a reflector 106 of mass mref and a tip 105 of mass mtip 105 , the respective moments of inertia Ip , Ilever 102 , Iref , Itip 105 are given by equation (7) below,

where ????p are the densities of the lever 102 and the particle respectively, and I0ref, I0tip 105, are the moments of inertia of the reflector 106 and the tip 105 about their respective centers of mass and lref is the distance of the centre of the reflector 106 from the axis of rotation.

Eqns. (4), (6) and (7) reveal that, to achieve high eigen-frequency, it is desirable for the tip 105 to possess small moment of inertia and the reflector 106 to be as small as possible. The reflector 106 is placed close to the axis of rotation. The lever 102 possess a small cross-sectional area Ac.

It is noted from Eqn (1) that the lever 102 length is proportional to the stiffness K? of the one or more compliant elements201. This implies that the eigen-frequency f0 is reduced for both very large and very small lengths of the lever 102. Thus, there exists an optimal length lopt of the lever 102 which maximizes the eigen-frequency of the probe for a specified range Z0.

The expression for the maximum eigen-frequency f0max and lopt are given by employing Eqn. (7) along with Eqns. (1) and (4). The resulting expressions are given by equations (8) and (9) below

It is noted from Eqns. (8) and (9) that the magnetic moment is proportional to its volume, i.e., to the cube of its width wp, while Ip is proportional to the fifth power of wp. Thus, Eqn. (9) reveals that f0max is weakly dependent on the dimensions of the magnetic particle.

Figure 5 shows an exemplary architecture of an Atomic force microscopy system 500 in accordance with some embodiments of the present disclosure;

The architecture may include an magnetically actuated active probe 100, an actuator 301, an Atomic force microscopy system 500 and a user 406. In some embodiments , the atomic microscopy system may be configured with the magnetically actuated active probe 100 and actuator 301 as shown in Fig : 5. In some other embodiments, some blocks of the atomic microscopy system may be remotely associated with the atomic microscope unit via, a wireless communication network ( not shown ). In some other embodiments, the magnetically actuated active probe 100 may be configured to operate in fluidic environments. For example, the magnetically actuated active probe 100 may be used to scan a liquid surface. In another embodiment, the magnetically actuated active probe 100 may be used to scan a solid surface submerged in a liquid.

The Atomic force microscopy system 500 may include a processor 403, an input/output interface, a memory 404 configured with an optical element 401 and a detector 402 for recording the linear displacement of the lever 102. The I/O interface 405 is configured to receive input from a user 406 and also to display the scanned images of the scan surface. A scan surface mounted on a stub, associated with the magnetically actuated active probe 100 is used to suspend the sample to be scanned. Typically, an optical system comprising an optical element 401 such as a Laser beam, is incident on the reflector 106 and the lever 102 is displayed (in one or more axes) while scanning the surface. Further, a detector 402 of the optical system receives reflected laser beam from the reflector 106. The reflected Laser beam is used to detect the displacement of the lever 102, rate of displacement and the any other information related to the displacement of the lever 102. The processor 403 is configured to receive the detector 402information related to displacement of the lever 102 from the detector 402. Upon receiving the information, the processor 403 generates an image of the scan surface magnetically actuated active probe 100lever 102. In an exemplified embodiment, the atomic microscopy system may be used to scan and generate a plurality of frames per second. As an example, if the time taken for the atomic microscopy system is 1/30th of a second, about 30 scanned surfaces can be scanned over a period of one second, provided the plurality of scan surfaces are already loaded with samples and placed under the reach of the probe. In an exemplified embodiment, the atomic microscopy system may be used to capture a change in topography of a sample. In another exemplified embodiment, the atomic microscopy system is used for scanning in fluidic environments. In yet another embodiment, the atomic microscopy system is used to scan biological samples. In yet another embodiment, the frequency of the magnetically actuated active probe 100 is only reduced by 15-25% when operated in fluidic environment such as water. The insignificant inertia of the probe and the components thereof in the present disclosure lead to a reduced effect of viscosity of a fluid in a fluidic environment on the resonance frequency of the probe in comparison to 70% reduction in prior art.

The atomic force microscopy comprise an actuator 301 which comprises a current carrying wire placed in the vicinity of one or more magnets 103 to generate magnetic field for the actuation of the magnetically actuated active probe 100 and is configured in a particular geometry to enable even distribution of magnetic field over the one or more magnets 103. The rise in temperature of the actuator 301 caused due to ohmic heating of the current carrying wire is reduced due to the particular geometry of the actuator 301. In an exemplified embodiment, the rise in temperature in the actuator 301 due to ohmic heating is in the range 5-20°C. For example, the particular geometry comprises one of geometry resembling ‘U’ shape and geometry resembling edged ‘U’ shape. In another embodiment, the magnetic field generated by the actuator 301 ranges from 200-500G. In another embodiment, current carrying wire of the actuator 301 is a copper wire of gain 35-45 G/A and of length 30-70µm. In an exemplified embodiment, the current carrying wire is made of copper. In an exemplified embodiment, the actuator 301 (400) was fabricated by arranging a copper foil between two sides of a macro-scale aluminium holder. Width of the copper foil is greater than that of the actuator 301. Subsequently, the width of the foil was reduced between the holders by using laser micro-machining. The laser system is a femto-second laser system.

As an example, the magnetic actuator 301 comprises a wire excited pulsating in a manner to support higher resonance frequency of the lever 102 of the magnetically actuated active probe 100. The wire is designed and fabricated such that length and cross-sectional area of the wire is small. The wire is arranged close in the vicinity of the one or more magnets 103 to produce high magnetic field, large bandwidth and minimize ohmic heating. As an example, the design of an embodiment of an actuator 301 can be optimized by the lumper parameter model for the actuator 301 where, the actuator 301 is a straight conductor of uniform cross section Aw and a finite length lw carrying current i. The magnetic field pointed along the Y-axis near the magnetic particle is given by the equation (10) below

Here the angles a1 and a2 consider the effect of the finite length of the actuator 301. The generation of current i results in ohmic heating of the conductor. To obtain the temperature distribution T(x) along the length of the conductor, one dimensional heat equation is employed. It is assumed that only conductive heat transfer takes place, so that the heat equation is given by the equation (11) below

where ? e??and k t are the electrical and the thermal conductivities of the material of actuator 301. The temperature profile along the length is obtained to be is shown in Equation 12 given below.

The temperature has a parabolic distribution with maximum rise in temperature occurring at x ??? lw / 2 and is given by the equation (13) below

So, an exemplified embodiment of an actuator 301 fabricated based on the lumped parameter model comprising insignificant loss due to ohmic heating thereby generates strong magnetic field per energy consumed. Further due to reduction in the ohmic heating, the rise in temperature of the actuator 301 is significantly reduced. Enhanced magnetic field strength, result in better actuation and thus better range of the magnetically actuated active probe 100, where the magnetically actuated active probe 100 comprising higher resonance frequency addresses the issues of the prior art, where the systems operating with higher ranges have lower resonance frequency and vice versa.

Figure 6 Shows a block diagram of an Atomic force microscopy system 500 in accordance with some embodiments of the present disclosure,

In some implementations, the atomic microscopy system may include data and modules. As an example, the data is stored in a memory 404 configured in the atomic microscopy system as shown in figure: 6. In one embodiment, the data may include a pre-stored data 502, scan data 503 and other data 504. In the illustrated figure:6 modules are described herein in detail.

In some embodiments, the data may be stored in the memory 404 in form of various data structures. Additionally, the data can be organized using data models, such as relational or hierarchical data models. The other data 504 may store data, including temporary data and temporary files, generated by the modules for performing the various functions of the data acquisition system. The pre-stored data 502 may comprise scanning parameters, processing parameters, processing instructions executable by a computer associated with the atomic microscope system,

In some embodiments, the data stored in the memory 404 may be processed by the modules of the atomic microscopy system. The modules may be stored within the memory 404. In an example, the modules communicatively coupled to the processor 403 configured in the Atomic force microscopy system 500, may also be present outside the memory 404 as shown in Fig.6 and implemented as hardware. As used herein, the term modules may refer to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor 403 (shared, dedicated, or group) and memory 404 that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. In some embodiments, the modules may include for example, an optical detection module, a receiving module 506, an image generation module, a I/O interface 405 module and other modules.

The other modules may be used to perform various miscellaneous functionalities of the atomic microscopy system. It will be appreciated that such aforementioned modules may be represented as a single module or a combination of different modules.

As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor 403 (shared, dedicated, or group) and memory 404 that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. In an embodiment, the other modules may be used to perform various miscellaneous functionalities of the data acquisition system. It will be appreciated that such modules may be represented as a single module or a combination of different modules. Furthermore, a person of ordinary skill in the art will appreciate that in an implementation, the one or more modules may be stored in the memory 404, without limiting the scope of the disclosure. The said modules when configured with the functionality defined in the present disclosure will result in a novel hardware.

The optical module is configured to project the optical beam from the optical element 401 on the reflector 106 continuously. The detector 402 module is configured to detect the reflected optical beam from the reflector 106 and store the data related to the linear displacement of the tip 105 of the lever 102 as scan data 503.

In an embodiment, the pre-stored data 502 may be accessed by the processor 403 to set the parameters of the magnetically actuated active probe 100 for scanning. In an exemplified embodiment, the parameters declared by a user 406 are stored as pre-stored data 502. After scanning, the receiving module 506 receives the information related to the displacement of lever, from the detector 402. The received information from the detector 402 may be stored as scan data 503. The image generating module, may retrieve the scan data 503 to generate an image of scan surface by the magnetically actuated active probe 100 using the information related to the displacement of the lever 102. The generated image(s) may be displayed or relayed further out of the Atomic force microscopy system 500 through I/O interface 405 module, where a user 406 can access the data

Figure 7 Shows a flowchart illustrating the method of fabrication of magnetically actuated active probe 100 in accordance with some embodiments of the present disclosure;

As illustrated in Fig.7, the method 600 includes one or more blocks illustrating a method of fabricating an magnetically actuated active probe 100. The method 600 may be described in the general context of computer executable instructions. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform specific functions or implement specific abstract data types.

The order in which the method 600 is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.

At block 601, the method 600 may include attaching a unmagnetized magnet particle to a probe, wherein the unmagnetized magnet particle is closer to a base of the probe. The machining tools comprise at least one of focused ion beam milling, nanofabrication in either a top-down approach with plurality of steps such as lithography, etching, deposition, lift-off or in a bottom-up approach with steps such as self-assembly and lift-off. The unmagnetized magnet particle is machined from above; wherein the lever 102 of the probe is machined from lateral and frontal directions. The plurality of current settings for machining comprise 9.3nA for coarser machining and 0.79nA for fine machining.
At block 602, the method 600 may machining using a machining tool, the unmagnetized magnet particle to form at least, one or more magnets 103 and one or more compliant elements201 between the one or more magnets 103

At block 603, the method 600 may include machining the probe to have a lever 102 of length 300-700 µm and width 30-70µm with a tip 105 having dimensions 3-18 µm using plurality of current settings for machining.

Figure: 8 shows the fabricated actuator in in accordance with some embodiments of the present disclosure;

A method includes one or more blocks illustrating a method of fabricating an actuator 301. The method may be described in the general context of computer executable instructions. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform specific functions or implement specific abstract data types.

The order in which the method is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.

The method may includemethod of fabrication of the actuator 301 , comprising,
attaching a conductive metallic strip onto a holding structure, providing electrical contacts to the strip; and machining the strip using a machining tool, to have the actuator 301 reduced to its final dimensions of width and thickness in the range of 30-70 µm, and a length of 300-700 µm, wherein the machining tool comprises at least one of laser micromachining, metal etching, and electroforming.
In an exemplified embodiment, the strip is made of copper, is electrically isolated from its holding structure;

In another embodiment a femtosecond pulsed laser source is operated at a wavelength of 800 nm, wherein the optical power is in the range of 200-700 mW, repetition rate in the range of 800 Hz- 1.4 kHz, and the pulse width in the range of 100-140 fs.

In an exemplified embodiment, the probe was machined by using Focused Ion Beam milling. The particle and the probe were machined from above so that their width and length were machined close to the specified value. The features were coarsely machined using ion bean milling at high ion current of 9.3 nA and subsequently at 0.79 nA fine machining. Subsequently, the particle was machined from the front to reduce its thickness to its final dimensions.

In an embodiment of the present disclosure, the magnetically actuated active probe 100 is used to scan real-time images of a moving components in a biological sample.

In an embodiment of the present disclosure, the magnetically actuated active probe 100 and the system thereof is used to scan a scan surface at high speed and still produce a high-resolution image of the scan surface. In an embodiment, the resonance frequency of the lever 102 is increases due to the design.

The terms "an embodiment", "embodiment", "embodiments", "the embodiment", "the embodiments", "one or more embodiments", "some embodiments", and "one embodiment" mean "one or more (but not all) embodiments of the invention(s)" unless expressly specified otherwise.

The terms "including", "comprising", “having” and variations thereof mean "including but not limited to", unless expressly specified otherwise. The enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms "a", "an" and "the" mean "one or more", unless expressly specified otherwise.

A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate the wide variety of possible embodiments of the invention.

When a single device or article is described herein, it will be readily apparent that more than one device/article (whether or not they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be readily apparent that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the invention need not include the device itself.

Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this description.

REFERRAL NUMERALS:

Reference number Description
100 Magnetically actuated active probe
101 Base member
102 Lever
103 One or more magnets
104 Support member
105 Tip
106 Reflector
201 One or more compliant elements
301 Actuator
401 Optical element
402 detector
403 Processor
404 Memory
405 I/O interface
406 user
500 Atomic force microscopy system
501 Data
502 Prestored data
503 Scan data
504 Other data
505 Optical detection module
506 Receiving module
507 Image Generating Module
508 I/O interface Module
509 Other Modules
,CLAIMS:1. A magnetically actuated active probe 100 of an atomic force microscope, comprising:
a base member 101;
a lever 102, wherein one end of the lever comprise the base member and the other end is defined with a tip 105;
one or more of magnets 103, fixed on the base member 101, wherein the lever 102 is positioned perpendicular to an axis passing through the center of mass of the one or more of magnets 103;
one or more compliant elements 201, disposed between the one or more of magnets, wherein the one or more compliant elements 201 are defined in gaps between each of the one or more of magnets 103 and a support member 104; wherein the active probe 100 is connected to the atomic force microscope unit through the support member 104;
wherein the one or more of magnets 103 are actuated to apply a torque on the one or more compliant elements 104 which produce torsional stress in the one or more compliant elements 104, causing linear displacement in a vertical direction for the tip through rigid body rotation of the lever 102.

2. The magnetically actuated active probe 100 as claimed in claim 1, wherein the one or more of magnets 103, one or more compliant elements 201 and the support member 104 are made from a single magnet particle.

3. The magnetically actuated active probe 100 as claimed in claim 1, wherein the tip of the lever is linearly displaced in a range of 250 nm to 1 µm.

4. The magnetically actuated active probe 100 as claimed in claim 1, wherein the range of linear displacement of the tip of the lever 105 is designed to be independent of the vertical resonance frequency of the magnetically actuated active probe 100.

5. The magnetically actuated active probe 100 as claimed in claim 1, wherein the magnetic moment of the magnetic particle 103 range 7 x 10-9Am2__to _11 x 10-9Am2.

6. The magnetically actuated active probe 100 as claimed in claim 1, further comprises a reflector 106 positioned on the lever 102 to detect the linear displacement of the lever 102.

7. The magnetically actuated active probe 100 as claimed in claim 1, wherein the cross-sectional area of the lever 102 ranges from 4 to 50 (µm)2.

8. The magnetically actuated active probe 100 as claimed in claim 1, wherein the length of the lever 102 is at least one the range of 80-100µm.

9. The magnetically actuated active probe 100 as claimed in claim 1, wherein the resonance frequency of the active probe 100 is 100-500KHz.

10. The magnetically actuated active probe 100 as claimed in claim 1, wherein the one or more of magnets 103 constitute a micro-ordered, hard ferromagnetic an alloy comprising at least two of neodymium, iron and boron.

11. The magnetically actuated active probe 100 as claimed in claim1, wherein the one or more magnets 103 are actuated by an actuator 301 that generates in the vicinity of the probe, magnetic fields with large electromagnetic bandwidth, comprising at least a current carrying wire.

12. The magnetically actuated active probe 100 as claimed in claim 1, wherein a dynamic lumped parameter model is used to optimize the design of the active probe 100.

13. An atomic force microscopy system 500, wherein the atomic force microscopy system 500 comprises,
a magnetically actuated active probe 100, wherein the magnetically actuated active probe 100 comprises,
a base member 101;
a lever 102, wherein one end of the lever comprise the base member and the other end is defined with a tip 105;
one or more of magnets 103, fixed on the base member 101, wherein the lever 102 is positioned perpendicular to the axis passing through the cross-sectional center of the one or more of magnets 103;
one or more compliant elements 201, disposed between the one or more of magnets 103, wherein the one or more compliant elements 201 are defined in gaps between each of the one or more of magnets 103 and a support member 104; wherein the magnetically actuated active probe 100 is connected to the atomic force microscope unit through the support member 104; wherein the magnetically actuated active probe 100 is configured to traverse a scan surface 010 for scanning at high speed;
an actuator 301 comprising at least a current carrying wire placed in the vicinity of the one or more magnets 103 to generate a magnetic field over high bandwidths for actuating the magnetically actuated active probe 100 and is configured to evenly distribute the magnetic field around the one or more magnets 103;
an optical element 401, configured to project an optical beam on the reflector 106 of the active probe 100;
a detector 402, configured to receive, and process reflected optical beam from the reflector 106 to detect displacement of the lever.
a processor 403,
a memory 404 communicatively coupled to the processor 403, wherein the processor 403 is configured to:
regulate the actuation of the magnetically actuated probe 100, by the actuator 301;
receive information from the detector related to displacement of the lever 102; and
generate a topography image of a scan surface 010 by the active probe 100 using the information related to displacement of the lever 102.

14. The atomic force microscopy system 500 as claimed in claim 13, wherein the atomic force microscopy system 500 further comprise a position mechanism places the actuator in the vicinity of the magnetically actuated active probe 100.

15. The atomic force microscopy system 500 as claimed in claim 13, wherein the atomic force microscopy system 500 further comprise an electronic circuit to generate the actuation current over high bandwidths.

16. The atomic force microscopy system 500 as claimed in claim 13, wherein the processor regulates the current supplied to the current carrying wire of the actuator 301 to regulate the actuation of the magnetically actuated active probe 100.

17. The atomic force microscopy system 500 as claimed in claim 13, wherein the actuator 301 comprises a current carrying wire placed in the vicinity of one or more magnets to generate magnetic field for the actuation of the active probe and is configured in a particular geometry to enable even distribution of magnetic field over the one or more magnets ; wherein the rise in temperature per unit length of the actuator caused due to ohmic heating of the current carrying wire is reduced due to the particular geometry of the actuator.

18. The atomic force microscopy system 500 as claimed in claim 13, wherein the particular geometry of the actuator 301 comprises one of geometry resembling ‘U’ shape and geometry resembling edged ‘U’ shape.

19. The atomic force microscopy system 500 as claimed in claim 13, wherein the magnetic field generated by the actuator in the vicinity of the probe ranges from 200-500G.

20. The atomic force microscopy system 500 as claimed in claim 13, wherein the current carrying wire of the actuator is a copper wire of magnetic field gain 35-45 G/A of cross-sectional dimensions 30-70µm and length 300-700 µm.

21. The atomic force microscopy system 500 as claimed in claim 13, wherein rise in temperature in the actuator due to ohmic heating is in the range 5-20°C.

22. The atomic force microscopy system 500 as claimed in claim 13, wherein the resonant frequency of the magnetically actuated active probe 100 is reduced only by 15-25% when operated in water.

23. A method of fabricating a magnetically actuated active probe 600, comprising,
attaching an at least one of unmagnetized magnet particle to a lever 102 of a probe, wherein the unmagnetized magnet particle is closer to a base of the probe;
machining using a machining tool, the unmagnetized magnet particle to form at least, one or more magnets and one or more compliant elements between the one or more magnets; and
machining the probe to have a lever of length 80-10µm and width2-5 µm with a tip having dimensions 3-18 µm using plurality of current settings for machining.

24. The fabrication of active probe 600 as claimed in claim 23, wherein the machining tool is a micro or nano-scale tool comprise at least one of focused ion beam milling, nanofabrication in either a top-down approach with plurality of steps such as lithography, etching, deposition, lift-off or in a bottom-up approach with steps such as self-assembly and lift-off.

25. The fabrication of active probe 600 as claimed in claim 23, wherein the unmagnetized magnet particle is machined from above; wherein the lever of the probe is machined from lateral and frontal directions.

26. The fabrication of active probe 600 as claimed in claim 23, wherein the plurality of current settings in the ion beam tool for machining comprise 9.3nA for coarser machining and 0.79nA for fine machining.

27. A method of fabrication of the actuator , comprising,
attaching a conductive metallic strip onto a holding structure;
providing electrical contacts to the strip; and
machining the strip using a machining tool, to have the actuator reduced to its final dimensions of width and thickness in the range of 30-70 µm, and a length of 300-700 µm.
28. The method of fabrication of the actuator as claimed in claim 27, wherein the machining tool comprises at least one of laser micromachining, metal etching, and electroforming.

29. The method of fabrication of the actuator as claimed in claim 27, wherein the strip is made of copper, is electrically isolated from its holding structure;

30. The method of fabrication of the actuator as claimed in claim 27, wherein a femtosecond pulsed laser source is operated at a wavelength of 800 nm, wherein the optical power is in the range of 200-700 mW, repetition rate in the range of 800 Hz- 1.4 kHz, and the pulse width in the range of 100-140 fs.