{"id":1047,"date":"2013-06-22T16:17:32","date_gmt":"2013-06-22T16:17:32","guid":{"rendered":"http:\/\/www.kam.k.leang.com\/academics\/?page_id=1047"},"modified":"2015-03-21T05:59:16","modified_gmt":"2015-03-21T05:59:16","slug":"nanopositioners","status":"publish","type":"page","link":"http:\/\/www.kam.k.leang.com\/academics\/nanopositioners\/","title":{"rendered":"High-performance Multi-axis Nanopositioners"},"content":{"rendered":"

Since 2007, we have been developing our own high-performance nanopositioning stages (nanopositioners) for research purposes. We specialize in serial-kinematic designs, and our nanopositioners have ranges up to 60 micrometers and dominant mechanical resonances as high as 150 kHz (unloaded). Photographs of our nanopositioners are shown below, in addition to related literature. If you are interested in obtaining a stage for research work, please contact Dr. Kam K. Leang for more info.<\/p>\n

First Generation Design<\/strong>
\nOur first generation serial-kinematic two-axis nanopositioner\u00a0design is shown below. \u00a0This design incorporates modular simple beam flexures and parts that are assembled using fasteners as shown Fig. 1 below. \u00a0As shown, the high-bandwidth x-axis is nested within the low-speed y-axis. The range is 10 um x 10 um, resonances are: x (29 kHz) and y (1.5 kHz).<\/p>\n

\"First<\/a>

Figure 1. First generation serial-kinematic two-axis nanopositioner with inertial cancellation. Range: 10 um x 10 um; Resonances: 29 kHz (x) and 1.5 kHz (y). \u00a0See reference Leang and Fleming (2009) below for more details about the design.<\/p><\/div>\n

More details about this design can be found in the following reference:<\/p>\n

“High-speed serial-kinematic AFM scanner: design and drive considerations”, K. K. Leang and A. J. Fleming Asian Journal of Control, Special issue on Advanced Control Methods for Scanning ProbeMicroscopy, Vol. 11, No. 2, pp. 144-153, 2009<\/em> [Click here to download manuscript in PDF<\/a>].<\/p>\n

 <\/p>\n

Second Generation Design<\/strong>
\nOur second generation design is a monolithic design shown below in Fig. 2. \u00a0In particular, the stage body is manufactured from 7075 aluminum using the wire electrical discharge machining (EDM) process to create a monolithic body. Compliant flexures are used to guide the motion of the sample stage along the x and y axes. Positioning of the sample in the vertical direction is achieved using a piezo-stack actuator embedded into the xpositioning stage. The dominant resonances in the x- and y-axes are measured at 10 and 2.4 kHz, respectively.<\/p>\n

\"Figure<\/a>

Figure 2. \u00a0Generation 2 three-axis serial-kinematic nanopositioner, range is 10 um x 10 um x 3 um and the resonances are: 10 kHz (x), 2.4 kHz (y) and >40 kHz (z).<\/p><\/div>\n

More details about this design can be found in the following reference:<\/p>\n

“Integrated strain and force feedback for high performance control of piezoelectric actuators,” A. J. Fleming and K. K. Leang, Sensors & Actuators: A. Physical, Vol. 161, pp. 256-265, 2010.<\/em>\u00a0[ Click here to download PDF<\/a> ]\n

 <\/p>\n

Third Generation Design (high-speed nanopositioners)<\/strong>
\nOur third generation design is also monolithic, but the mechanical resonances were optimized for high-speed positioning. \u00a0More specifically, the compliant flexures had improved vertical stiffness to minimize out-of-plane motion. \u00a0The flexures were also strategically placed to minimize the sample platform\u2019s tendency to rotate at high frequencies. \u00a0There are two examples below shown in Fig. 3 and 4, where the design in Fig. 4 was used for high-speed AFM imaging at frame rates that exceeded 70 frames per second.<\/p>\n

\"Figure<\/a>

Figure 3. Three-axis serial-kinematic nanopositioner, with range of 10 um x 10 um x 2 um, resonance of 12 kHz (z), 5 kHz (y), and >50 kHz (z).<\/p><\/div>\n

\"Figure<\/a>

Figure 4. High-speed serial-kinematic nanopositioner. \u00a0Range: 10 um x 10 um x 2 um, resonances: 24 kHz (z), 6 kHz (y), and >70 kHz (z).<\/p><\/div>\n

More details about this design can be found in the following reference:<\/p>\n

“Dual-Stage Repetitive Control with Prandtl-Ishlinskii Hysteresis Inversion for Piezo-Based Nanopositioning”, Y. Shan and K. K. Leang, Mechatronics, Special Issue on Mechatronic Systems for Micro- and Nanoscale Applications, Vol. 22, pp. 271 – 281, 2012.<\/em> [ Click here to download PDF <\/a>]\n

“Design and control of a three-axis serial-kinematic high-bandwidth nanopositioner”, B. J. Kenton and K. K . Leang, IEEE\/ASME Trans. on Mechatronics, Vol. 17, No. 2, pp.\u00a0356 – 369, 2012.\u00a0<\/em>[ Click here to download PDF<\/a> ]\n

 <\/p>\n

Long-Range Stages<\/strong>
\nThe following are examples of our long-range, serial kinematic nanopositioners. \u00a0These stages are designed such that their first dominant resonant mode is in the actuation direction. \u00a0As such, the stage dynamics can be modeled by basic second-order transfer function models.<\/p>\n

\n
\"Long<\/a><\/dt>\n
Long range three-axis nanopositioner. Range: 40 um x 40 um x 3-10 um; Resonances: 700 Hz (x), 500 Hz (y) and >30 kHz (z).<\/dd>\n<\/dl>\n
\"Long-range<\/a>

Long range three-axis nanopositioner. \u00a0Specifications are the same as the design shown above.<\/p><\/div>\n

Publications related to nanopositioners, nanopositioning, and piezoactuators:<\/strong><\/p>\n

<\/a><\/form>

2022<\/h3>
64.<\/div>
\"Low-Coupling<\/div>

W. S. Nagel, S. Andersson, G. Clayton; K. K. Leang<\/p>

Low-Coupling Hybrid Parallel-Serial-Kinematic Nanopositioner with Nonorthogonal Flexure: Nonlinear Design and Control Journal Article<\/span> <\/p>

In: <\/span>IEEE\/ASME Transactions on Mechatronics, <\/span>vol. 27, <\/span>iss. 5, <\/span>pp. 3683-3693, <\/span>2022<\/span>.<\/p>

Abstract<\/a><\/span> | BibTeX<\/a><\/span><\/p>

@article{NagelWS_2022_Tmech,
\r\ntitle = {Low-Coupling Hybrid Parallel-Serial-Kinematic Nanopositioner with Nonorthogonal Flexure: Nonlinear Design and Control},
\r\nauthor = {W. S. Nagel, S. Andersson, G. Clayton and K. K. Leang},
\r\nyear  = {2022},
\r\ndate = {2022-10-01},
\r\nurldate = {2021-11-18},
\r\njournal = {IEEE\/ASME Transactions on Mechatronics},
\r\nvolume = {27},
\r\nissue = {5},
\r\npages = {3683-3693},
\r\nabstract = {This article focuses on the design and high-precision control of a new dual-stage, three-axis hybrid parallel-serial-kinematic nanopositioner developed specifically for feature-tracking applications with arbitrary scanning directions. Dual-actuation is achieved by integrating a three-axis shear piezoelectric actuator into the large-range planar stage. A novel nonorthogonal compliant motion-amplifying mechanism which reorients the lateral sample-platform displacement to align with the principal directions of the input piezoactuators is used to minimize parasitic (coupling) motion. A nonlinear rigid-link model and finite element analysis (FEA) are used to optimize over the orientation parameter during the design process. A prototype stage is manufactured and tested, and the lateral and vertical travel ranges are approximately 18 \u00d7 21 and 1 \u03bc m, respectively, with secondary lateral actuation in the range of 1 \u00d7 1 \u03bc m. Coupling in the long-range stage is below -31 dB for both axes, an estimated 51 to 86% reduction compared to a traditional perpendicular-mechanism design. The measured dominant resonances for the lateral directions of the long-range stage are approximately 1.4 kHz, while short-range positioner resonances are approximately 11 and 40 kHz for the lateral and vertical directions, respectively. The design of a new feedforward-feedback controller is described, and the controller is implemented with field-programmable gate array (FPGA) hardware, where individual actuator contributions are intuitively determined by shaping the frequency response of their relative and summed displacements. An inverse hysteresis operator is used to linearize the plant behavior for effective motion control. Experimental tracking and atomic force microscopy (AFM) imaging results are presented to demonstrate the performance of the new mechanical and control system designs.},
\r\nkeywords = {},
\r\npubstate = {published},
\r\ntppubtype = {article}
\r\n}
\r\n<\/pre><\/div>
Close<\/a><\/p><\/div>
This article focuses on the design and high-precision control of a new dual-stage, three-axis hybrid parallel-serial-kinematic nanopositioner developed specifically for feature-tracking applications with arbitrary scanning directions. Dual-actuation is achieved by integrating a three-axis shear piezoelectric actuator into the large-range planar stage. A novel nonorthogonal compliant motion-amplifying mechanism which reorients the lateral sample-platform displacement to align with the principal directions of the input piezoactuators is used to minimize parasitic (coupling) motion. A nonlinear rigid-link model and finite element analysis (FEA) are used to optimize over the orientation parameter during the design process. A prototype stage is manufactured and tested, and the lateral and vertical travel ranges are approximately 18 \u00d7 21 and 1 \u03bc m, respectively, with secondary lateral actuation in the range of 1 \u00d7 1 \u03bc m. Coupling in the long-range stage is below -31 dB for both axes, an estimated 51 to 86% reduction compared to a traditional perpendicular-mechanism design. The measured dominant resonances for the lateral directions of the long-range stage are approximately 1.4 kHz, while short-range positioner resonances are approximately 11 and 40 kHz for the lateral and vertical directions, respectively. The design of a new feedforward-feedback controller is described, and the controller is implemented with field-programmable gate array (FPGA) hardware, where individual actuator contributions are intuitively determined by shaping the frequency response of their relative and summed displacements. An inverse hysteresis operator is used to linearize the plant behavior for effective motion control. Experimental tracking and atomic force microscopy (AFM) imaging results are presented to demonstrate the performance of the new mechanical and control system designs.<\/div>
Close<\/a><\/p><\/div><\/div><\/div>
63.<\/div>
\"Discrete<\/div>
William Nagel, Aleksandra Mitrovic, Garrett Clayton, Kam K. Leang\r\n<\/p>
Discrete Input-Output Sliding-Mode Control with Range Compensation: Application in High-Speed Nanopositioning Proceedings Article<\/span> <\/p>
In: <\/span>American Control Conference, June 8-11, <\/span>2022<\/span>.<\/p>
BibTeX<\/a><\/span><\/p>
@inproceedings{NagelWS_2022_ACC,
\r\ntitle = {Discrete Input-Output Sliding-Mode Control with Range Compensation: Application in High-Speed Nanopositioning},
\r\nauthor = {William Nagel, Aleksandra Mitrovic, Garrett Clayton, Kam K. Leang
\r\n},
\r\nyear  = {2022},
\r\ndate = {2022-06-08},
\r\nurldate = {2022-06-08},
\r\nbooktitle = {American Control Conference, June 8-11},
\r\nkeywords = {},
\r\npubstate = {published},
\r\ntppubtype = {inproceedings}
\r\n}
\r\n<\/pre><\/div>
Close<\/a><\/p><\/div><\/div><\/div>
62.<\/div>
\"Long-Range<\/div>
W. S. Nagel<\/p>
Long-Range Low-Coupling Dual-Stage Nanopositioning: Design and Control for High-Speed Atomic Force Microscopy PhD Thesis<\/span> <\/p>
2022<\/span>.<\/p>
BibTeX<\/a><\/span><\/p>
@phdthesis{NagelW_2022_PHD,
\r\ntitle = {Long-Range Low-Coupling Dual-Stage Nanopositioning: Design and Control for High-Speed Atomic Force Microscopy},
\r\nauthor = {W. S. Nagel},
\r\nyear  = {2022},
\r\ndate = {2022-04-18},
\r\nkeywords = {},
\r\npubstate = {published},
\r\ntppubtype = {phdthesis}
\r\n}
\r\n<\/pre><\/div>
Close<\/a><\/p><\/div><\/div><\/div>
2021<\/h3>
61.<\/div>
\"Closed-loop<\/div>
A. Mitrovic, W. S. Nagel, K. K. Leang; G. M. Clayton <\/p>
Closed-loop Range-Based Control of Dual-Stage Nanopositioning Systems<\/a> Journal Article<\/span> <\/p>
In: <\/span>IEEE\/ASME Transactions on Mechatronics, <\/span>vol. 26, <\/span>iss. 3, <\/span>pp. 1412-1421, <\/span>2021<\/span>.<\/p>
Abstract<\/a><\/span> | Links<\/a><\/span> | BibTeX<\/a><\/span><\/p>
@article{MitrovicA_2019_TmechSpecialIssue,
\r\ntitle = {Closed-loop Range-Based Control of Dual-Stage Nanopositioning Systems},
\r\nauthor = {A. Mitrovic, W. S. Nagel, K. K. Leang and G. M. Clayton },
\r\ndoi = {10.1109\/TMECH.2020.3020047},
\r\nyear  = {2021},
\r\ndate = {2021-06-01},
\r\nurldate = {2021-06-01},
\r\njournal = {IEEE\/ASME Transactions on Mechatronics},
\r\nvolume = {26},
\r\nissue = {3},
\r\npages = {1412-1421},
\r\nabstract = {In this paper, a closed-loop control framework for dual-stage nanopositioning systems is presented that allows the user to allocate control efforts to the individual actuators based on their range capabilities. Recent work by the authors has focused on range-based control of dual-stage actuators implemented as a prefilter, which assumes that each individual actuator has sensor feedback enabling them to be controlled separately. This paper seeks to address the problem of range-based control of dual-stage systems when sensor measurements are only available from the total output of the system, a commonly encountered design. This is a significant departure from previous work since the range-based filter is included in the dual-stage system feedback loop and stability becomes a concern. In this work, the controller is presented, stability conditions are determined, and imaging experiments are performed on an atomic force microscope (AFM). Tracking results show that the root-mean-square (RMS) tracking error for various triangular reference trajectories is improved with the presented range-based control structure by up to 50% compared to frequency-based methods.},
\r\nkeywords = {},
\r\npubstate = {published},
\r\ntppubtype = {article}
\r\n}
\r\n<\/pre><\/div>
Close<\/a><\/p><\/div>
In this paper, a closed-loop control framework for dual-stage nanopositioning systems is presented that allows the user to allocate control efforts to the individual actuators based on their range capabilities. Recent work by the authors has focused on range-based control of dual-stage actuators implemented as a prefilter, which assumes that each individual actuator has sensor feedback enabling them to be controlled separately. This paper seeks to address the problem of range-based control of dual-stage systems when sensor measurements are only available from the total output of the system, a commonly encountered design. This is a significant departure from previous work since the range-based filter is included in the dual-stage system feedback loop and stability becomes a concern. In this work, the controller is presented, stability conditions are determined, and imaging experiments are performed on an atomic force microscope (AFM). Tracking results show that the root-mean-square (RMS) tracking error for various triangular reference trajectories is improved with the presented range-based control structure by up to 50% compared to frequency-based methods.<\/div>
Close<\/a><\/p><\/div>