Making a commercial atomic force microscope more accurate and faster using positive position feedback control

Mahmood, I. A.; Moheimani, S. O. Reza
June 2009
Review of Scientific Instruments;Jun2009, Vol. 80 Issue 6, p063705
Academic Journal
This paper presents experimental implementation of a positive position feedback (PPF) control scheme for vibration and cross-coupling compensation of a piezoelectric tube scanner in a commercial atomic force microscope (AFM). The AFM is a device capable of generating images with extremely high resolutions down to the atomic level. It is also being used in applications that involve manipulation of matter at a nanoscale. Early AFMs were operated in open loop. Consequently, they were susceptible to piezoelectric creep, thermal drift, hysteresis nonlinearity, and scan-induced vibration. These effects tend to distort the generated image and slow down the scanning speed of the device. Recently, a new generation of AFMs has emerged that utilizes position sensors to measure displacements of the scanner in three dimensions. These AFMs are equipped with feedback control loops that work to minimize the adverse effects of hysteresis, piezoelectric creep, and thermal drift on the obtained image using proportional-plus-integral (PI) controllers. These feedback controllers are often not designed to deal with the highly resonant nature of an AFM’s scanner nor with the cross coupling between various axes. In this paper we illustrate the improvement in accuracy and imaging speed that can be achieved by using a properly designed feedback controller such as a PPF controller. Such controllers can be incorporated into most modern AFMs with minimal effort since they can be implemented in software with the existing hardware. Experimental results show that by implementing the PPF control scheme, relatively good images in comparison with a well-tuned PI controller can still be obtained up to line scan of 60 Hz.


Related Articles

  • Mechanical writing of n-type conductive layers on the SrTiO3 surface in nanoscale. Wang, Yuhang; Zhao, Kehan; Shi, Xiaolan; Li, Geng; Xie, Guanlin; Lai, Xubo; Ni, Jun; Zhang, Liuwan // Scientific Reports;6/5/2015, p10841 

    The fabrication and control of the conductive surface and interface on insulating SrTiO3 bulk provide a pathway for oxide electronics. The controllable manipulation of local doping concentration in semiconductors is an important step for nano-electronics. Here we show that conductive patterns...

  • Micromechanical sensors for chemical and physical measurements. Wachter, E.A.; Thundat, T. // Review of Scientific Instruments;Jun95, Vol. 66 Issue 6, p3662 

    Discusses a novel class of highly sensitive sensors that are based on commercially available microcantilevers, such as those used in atomic force microscopy. Microcantilever preparation; Cantilever exposure and monitoring; Mercury vapor; Relative humidity; Ultraviolet radiation; Instrumental...

  • Nanofabrication of sensors on cantilever probe tips for scanning multiprobe microscopy. Luo, K.; Shi, Z. // Applied Physics Letters;1/15/1996, Vol. 68 Issue 3, p325 

    Describes a method for nanofabricating sensors on cantilever probe tips used in atomic force microscopy. Use of voltage pulses to evaporate and create a nanometer-scale hole; Applicability of the hole in the metal film as a mask for further device fabrication; Indications of thermal images of...

  • Interdigital cantilevers for atomic force microscopy. Manalis, S. R.; Minne, S. C.; Atalar, A.; Quate, C. F. // Applied Physics Letters;12/16/1996, Vol. 69 Issue 25, p3944 

    We present a sensor for the atomic force microscope (AFM) where a silicon cantilever is micromachined into the shape of interdigitated fingers that form a diffraction grating. When detecting a force, alternating fingers are displaced while remaining fingers are held fixed. This creates a phase...

  • Independent detection of vertical and lateral forces with a sidewall-implanted dual-axis piezoresistive cantilever. Chui, B. W.; Kenny, T. W.; Mamin, H. J.; Terris, B. D.; Rugar, D. // Applied Physics Letters;3/16/1998, Vol. 72 Issue 11 

    A dual-axis atomic force microscope (AFM) cantilever with independent piezoresistive sensors has been developed for simultaneous detection of vertical and lateral forces. The cantilever consists of a flat, triangular probe connected to a base by four tall, narrow ribs. The vertically compliant...

  • Limits of force microscopy. Smith, D.P.E. // Review of Scientific Instruments;May95, Vol. 66 Issue 5, p3191 

    Determines the quantum limited sensitivity of the atomic force microscope (AFM) using common optical detection techniques. Energy resolution of the microscope; Periodic forces detected in vacuum operation; Common features of the AFM with a resonant-bar gravitational antenna.

  • Parallel atomic force microscopy using cantilevers with integrated piezoresistive sensors and.... Minne, S.C.; Manalis, S.R. // Applied Physics Letters;12/25/1995, Vol. 67 Issue 26, p3918 

    Presents a model for atomic force microscopy using parallel cantilevers. Use of integrated piezoresistive silicon sensor and piezoelectric zinc oxide actuator in the cantilevers; Significance of the integration of detector and actuator; Deflection provided by the actuator at varied frequencies.

  • High-speed atomic force microscopy using an integrated actuator and optical lever detection. Manalis, S.R.; Minne, S.C.; Atalar, A.; Quate, C.F. // Review of Scientific Instruments;Sep96, Vol. 67 Issue 9, p3294 

    Describes high-speed atomic force microscopy using an integrated actuator and optical lever detection. Limiting of the bandwidth by a mechanical resonance; Scanning of the images; Verification that the tip/sample force is constant by monitoring the cantilever stress with an implanted piezoresistor.

  • Attractive-mode atomic force microscopy with optical detection in an orthogonal cantilever/sample configuration. Yang, P. C.; Chen, Y.; Vaez-Iravani, M. // Journal of Applied Physics;3/15/1992, Vol. 71 Issue 6, p2499 

    Describes an attractive-mode atomic force microscope in which the cantilever is held orthoganally. Description of the basic design of the system; Method used to describe the theory of detection; Scheme used to generate a signal.


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics