@article{MRL_AFM_Low_cost_AFM,

title = {A modular low-cost atomic force microscope for precision mechatronics education},

author = {Fangzhou Xia and James Quigley and Xiaotong Zhang and Chen Yang and Yi Wang and Kamal Youcef-Toumi},

url = {https://www.sciencedirect.com/science/article/pii/S0957415821000441},

doi = {https://doi.org/10.1016/j.mechatronics.2021.102550},

issn = {0957-4158},

year  = {2021},

date = {2021-04-15},

journal = {Mechatronics},

volume = {76},

pages = {102550},

publisher = {ScienceDirect},

abstract = {Precision mechatronics and nanotechnology communities can both benefit from a course centered around an Atomic Force Microscope (AFM). Developing an AFM can provide precision mechatronics engineers with a valuable multidisciplinary hands-on training experience. In return, such expertise can be applied to the design and implementation of new precision instruments, which helps nanotechnology researchers make new scientific discoveries. However, existing AFMs are not suitable for mechatronics education due to their different original design intentions. Therefore, we address this challenge by developing an AFM intended for precision mechatronics education. This paper presents the design and implementation of an educational AFM and its corresponding precision mechatronics class. The modular educational AFM is low-cost (≤$4,000) and easy to operate. The cost reduction is enabled by new subsystem development of a buzzer-actuated scanner and demodulation electronics designed to interface with a myRIO data acquisition system. Moreover, the use of an active cantilever probe with piezoresistive sensing and thermomechanical actuation significantly reduced experiment setup overhead with improved operational safety. In the end, the developed AFM capabilities are demonstrated with imaging results. The paper also showcases the course design centered around selected subsystems. The new AFM design allows scientific-method-based learning, maximizes utilization of existing resources, and offers potential subsystem upgrades for high-end research applications. The presented instrument and course can help connect members of both the AFM and the mechatronics communities to further develop advanced techniques for new applications.},

keywords = {Experimentation, Fabrication, Instrumentation, Mechatronic Design, Nanoscale video imaging for dynamic process visualization, Nanotechnology, Physical System Modeling},

pubstate = {published},

tppubtype = {article}

}

@article{MRL_AFM_Charge_Controller_PBFODC,

title = {Modeling and Control of Piezoelectric Hysteresis: A Polynomial-Based Fractional Order Disturbance Compensation Approach},

author = {Chen Yang and Nicolas Verbeek and Fangzhou Xia and Yi Wang and Kamal Youcef-Toumi},

url = {https://ieeexplore.ieee.org/document/9027124},

doi = {10.1109/TIE.2020.2977567},

issn = {1557-9948},

year  = {2020},

date = {2020-03-06},

journal = {IEEE Transactions on Industrial Electronics},

publisher = {IEEE},

abstract = {Piezoelectric hysteresis is a critical issue that significantly degrades the motion accuracy of piezo-actuated nanopositioners. Such an issue is difficult to be precisely modeled and compensated for, primarily due to its asymmetric, rate and input amplitude dependent characteristics. This paper proposes a novel method to deal with this challenge. Specifically, a polynomial-based fractional order disturbance model is proposed to accommodate and characterize the complex hysteresis effect. In this model, the rate dependency is captured by a general method of implementing curve fitting in Bode magnitude plot. The inverse model for control purposes is immediately available from the original one. The proposed method does not require expensive computational resources. In fact, this paper shows that this controller can be easily implemented in an analog manner, which brings the advantages of high-bandwidth and low-cost. Extensive modeling and tracking experiments are carried out to demonstrate the effectiveness of the proposed method. It is shown that the piezoelectric hysteresis nonlinearity can be significantly suppressed over a wide bandwidth.},

keywords = {Control Theory, Experimentation, Nanoscale video imaging for dynamic process visualization, Nanotechnology, Physical System Modeling, Simulation},

pubstate = {published},

tppubtype = {article}

}

@article{MRL_AFM_coated_probe,

title = {Lights Out! Nano-Scale Topography Imaging of Sample Surface in Opaque Liquid Environments with Coated Active Cantilever Probes},

author = {Fangzhou Xia and Chen Yang and Yi Wang and Kamal Youcef-Toumi and Christoph Reuter and Tzvetan Ivanov and Mathias Holz and Ivo W Rangelow},

url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6669515/},

doi = {10.3390/nano9071013},

year  = {2019},

date = {2019-07-09},

journal = {Nanomaterials},

volume = {9},

number = {7},

pages = {1013},

publisher = {Multidisciplinary Digital Publishing Institute},

abstract = {Atomic force microscopy is a powerful topography imaging method used widely in nanoscale metrology and manipulation. A conventional Atomic Force Microscope (AFM) utilizes an optical lever system typically composed of a laser source, lenses and a four quadrant photodetector to amplify and measure the deflection of the cantilever probe. This optical method for deflection sensing limits the capability of AFM to obtaining images in transparent environments only. In addition, tapping mode imaging in liquid environments with transparent sample chamber can be difficult for laser-probe alignment due to multiple different refraction indices of materials. Spurious structure resonance can be excited from piezo actuator excitation. Photothermal actuation resolves the resonance confusion but makes optical setup more complicated. In this paper, we present the design and fabrication method of coated active scanning probes with piezoresistive deflection sensing, thermomechanical actuation and thin photoresist polymer surface coating. The newly developed probes are capable of conducting topography imaging in opaque liquids without the need of an optical system. The selected coating can withstand harsh chemical environments with high acidity (e.g., 35% sulfuric acid). The probes are operated in various opaque liquid environments with a custom designed AFM system to demonstrate the imaging performance. The development of coated active probes opens up possibilities for observing samples in their native environments.},

keywords = {Experimentation, Fabrication, Full text available online, Instrumentation, Mechatronic Design, Nanoscale video imaging for dynamic process visualization, Nanotechnology, Physical System Modeling, Visualization},

pubstate = {published},

tppubtype = {article}

}

@article{MRL_AFM_Charge_Controller_Self_Compensating,

title = {Charge Controller With Decoupled and Self-Compensating Configurations for Linear Operation of Piezoelectric Actuators in a Wide Bandwidth},

author = {Chen Yang and Changle Li and Fangzhou Xia and Yanhe Zhu and Jie Zhao and Kamal Youcef-Toumi},

url = {https://ieeexplore.ieee.org/document/8466119},

doi = {10.1109/TIE.2018.2868321},

year  = {2018},

date = {2018-09-14},

journal = {IEEE Transactions on Industrial Electronics},

volume = {66},

number = {7},

pages = {5392--5402},

publisher = {IEEE},

abstract = {Charge control is a well-known sensorless approach to operate piezoelectric actuators, which has been proposed for more than 30 years. However, it is rarely used in industry because the implemented controllers suffer from the issues of limited low-frequency performance, long settling time, floating-load, and loss of stroke, etc. In this paper, a novel controller circuit dedicated to overcome these issues is presented. In the proposed scheme, a grounded-load charge controller with decoupled configuration is developed, which separates high-frequency and low-frequency paths, thus achieving arbitrarily low transition frequency without increasing the settling time. Based on this, a self-compensating configuration is further proposed and integrated into the controller circuit, which makes full use of controller output to improve its own control performance at low frequencies. Experimental results show that the presented charge controller can effectively reduce more than 88% of the hysteretic nonlinearity even when operating close to the transition frequency. To demonstrate its practical value, we then integrate it into a custom-designed high-speed atomic force microscope system. By comparing images obtained from using voltage drive and charge controller, it is clear that the piezoelectric hysteresis has been significantly reduced in a wide bandwidth.},

keywords = {Control Theory, Experimentation, Instrumentation, Nanoscale video imaging for dynamic process visualization, Nanotechnology, Physical System Modeling, Simulation},

pubstate = {published},

tppubtype = {article}

}

@article{MRL_AFM_active_probe_review,

title = {Review Article: Active scanning probes: A versatile toolkit for fast imaging and emerging nanofabrication},

author = {Ivo W Rangelow and Tzvetan Ivanov and Ahmad Ahmad and Marcus Kaestner and Claudia Lenk and Iman Soltani Bozchalooi and Fangzhou Xia and Kamal Youcef-Toumi and Mathias Holz and Alexander Reum},

url = {https://avs.scitation.org/doi/full/10.1116/1.4992073},

doi = {10.1116/1.4992073},

year  = {2017},

date = {2017-11-03},

journal = {Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena},

volume = {35},

number = {6},

pages = {06G101},

publisher = {American Vacuum Society},

abstract = {With the recent advances in the field of nanotechnology, measurement and manipulation requirements at the nanoscale have become more stringent than ever before. In atomic force microscopy, high-speed performance alone is not sufficient without considerations of other aspects of the measurement task, such as the feature aspect ratio, required range, or acceptable probe-sample interaction forces. In this paper, the authors discuss these requirements and the research directions that provide the highest potential in meeting them. The authors elaborate on the efforts toward the downsizing of self-sensed and self-actuated probes as well as on upscaling by active cantilever arrays. The authors present the fabrication process of active probes along with the tip customizations carriedout targeting specific application fields. As promising application in scope of nanofabrication, field emission scanning probe lithography is introduced. The authors further discuss their control and design approach. Here, microactuators, e.g., multilayer microcantilevers, and macroactuators, e.g., flexure scanners, are combined in order to simultaneously meet both the range and speed requirements of a new generation of scanning probe microscopes.},

keywords = {Instrumentation, Mechatronic Design, Nanoscale video imaging for dynamic process visualization, Nanotechnology, Physical System Modeling, Visualization},

pubstate = {published},

tppubtype = {article}

}

@article{MRL_AFM_LRHS_imaging,

title = {Design and control of multi-actuated atomic force microscope for large-range and high-speed imaging},

author = {Iman Soltani Bozchalooi and Andrew Careaga Houck and Jwaher M. AlGhamdi and Kamal Youcef-Toumi},

url = {http://www.sciencedirect.com/science/article/pii/S0304399115300528 https://www.youtube.com/watch?v=PQ-zE6wA61c},

doi = {https://doi.org/10.1016/j.ultramic.2015.10.016},

issn = {0304-3991},

year  = {2016},

date = {2016-01-01},

volume = {160},

pages = {213 - 224},

abstract = {This paper presents the design and control of a high-speed and large-range atomic force microscopy (AFM). A multi-actuation scheme is proposed where several nano-positioners cooperate to achieve the range and speed requirements. A simple data-based control design methodology is presented to effectively operate the AFM scanner components. The proposed controllers compensate for the coupled dynamics and divide the positioning responsibilities between the scanner components. As a result, the multi-actuated scanner behavior is equivalent to that of a single X–Y–Z positioner with large range and high speed. The scanner of the designed AFM is composed of five nano-positioners, features 6μm out-of-plane and 120μm lateral ranges and is capable of high-speed operation. The presented AFM has a modular design with laser spot size of 3.5μm suitable for small cantilever, an optical view of the sample and probe, a conveniently large waterproof sample stage and a 20MHz data throughput for high resolution image acquisition at high imaging speeds. This AFM is used to visualize etching of calcite in a solution of sulfuric acid. Layer-by-layer dissolution and pit formation along the crystalline lines in a low pH environment is observed in real time.},

keywords = {Control Theory, Experimentation, Fabrication, Instrumentation, Mechatronic Design, Nanoscale video imaging for dynamic process visualization, Nanotechnology, Simulation, Visualization},

pubstate = {published},

tppubtype = {article}

}

@article{MRL_AFM_Surface_Wetting_Poly_Surfaces,

title = {Surface and wetting characteristics of textured bisphenol-A based polycarbonate surfaces: Acetone-induced crystallization texturing methods},

author = {Ahmed Owais and Mazen M Khaled and Bekir S Yilbas and Numan Abu-Dheir and Kripa K Varanasi and Kamal Y Toumi},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/app.43074},

doi = {https://doi.org/10.1002/app.43074},

issn = {43074},

year  = {2015},

date = {2015-11-12},

journal = {Journal of Applied Polymer Science},

volume = {133},

number = {14},

publisher = {Wiley},

abstract = {ABSTRACT Polycarbonate (PC) sheet is a promising material for facile patterning to induce hydrophobic self-cleaning and dust repelling properties for photovoltaic panels’ protection. An investigation to texture PC sheet surfaces to develop a self-cleaning structure using solvent induced-crystallization is carried out using acetone. Acetone is applied in both liquid and vapor states to generate a hierarchically structured surface that would improve its contacts angle and therefore improve hydrophobicity. The surface texture is investigated and characterized using atomic force microscopy, contact angle technique (Goniometer), optical microscopy, ultraviolet-visible spectroscopy (UV–vis) and Fourier transform infrared spectroscopy. The findings revealed that the liquid acetone-induced crystallization of PC surface leads to a hierarchal and hydrophobic surface with an average contact angle of 135° and average transmittance <2%. However, the acetone vapor induced-crystallization results in a slightly hydrophilic hierarchal textured surface with high transmittance; in which case, average contact angle of 89° and average transmittance of 69% are achieved. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43074.},

keywords = {Nanoscale video imaging for dynamic process visualization, Nanotechnology, Physical System Modeling, Simulation, Visualization},

pubstate = {published},

tppubtype = {article}

}

@article{MRL_Multi_Eigenmode,

title = {Multi-eigenmode control for high material contrast in bimodal and higher harmonic atomic force microscopy},

author = {Andreas Schuh and Iman Soltani Bozchalooi and Ivo W Rangelow and Kamal Youcef-Toumi},

url = {https://doi.org/10.1088/0957-4484/26/23/235706},

doi = {10.1088/0957-4484/26/23/235706},

year  = {2015},

date = {2015-05-01},

journal = {Nanotechnology},

volume = {26},

number = {23},

pages = {235706},

publisher = {IOP Publishing},

abstract = {High speed imaging and mapping of nanomechanical properties in atomic force microscopy (AFM) allows the observation and characterization of dynamic sample processes. Recent developments involve several cantilever frequencies in a multifrequency approach. One method actuates the first eigenmode for topography imaging and records the excited higher harmonics to map nanomechanical properties of the sample. To enhance the higher frequencies’ response two or more eigenmodes are actuated simultaneously, where the higher eigenmode(s) are used to quantify the nanomechanics. In this paper, we combine each imaging methodology with a novel control approach. It modifies the Q factor and resonance frequency of each eigenmode independently to enhance the force sensitivity and imaging bandwidth. It allows us to satisfy the different requirements for the first and higher eigenmode. The presented compensator is compatible with existing AFMs and can be simply attached with minimal modifications. Different samples are used to demonstrate the improvement in nanomechanical contrast mapping and imaging speed of tapping mode AFM in air. The experiments indicate most enhanced nanomechanical contrast with low Q factors of the first and high Q factors of the higher eigenmode. In this scenario, the cantilever topography imaging rate can also be easily improved by a factor of 10.},

keywords = {Algorithms, Nanoscale video imaging for dynamic process visualization, Nanotechnology, Physical System Modeling, Simulation},

pubstate = {published},

tppubtype = {article}

}

@article{MRL_AFM_Agreecan_Nanoscale_Solid,

title = {Aggrecan Nanoscale Solid–Fluid Interactions Are a Primary Determinant of Cartilage Dynamic Mechanical Properties},

author = {Hadi Nia and Lin Han and Iman Soltani and Peter Roughley and Kamal Youcef-Toumi and Alan Grodzinsky and Christine Ortiz},

doi = {10.1021/nn5062707},

issn = {2614-2625},

year  = {2015},

date = {2015-03-10},

journal = {ACS nano},

volume = {9},

publisher = {ACS},

abstract = {Poroelastic interactions between interstitial fluid and the extracellular 

matrix of connective tissues are critical to biological and pathophysiological functions 

involving solute transport, energy dissipation, self-stiffening and lubrication. However, 

the molecular origins of poroelasticity at the nanoscale are largely unknown. Here, the 

broad-spectrum dynamic nanomechanical behavior of cartilage aggrecan monolayer is 

revealed for the first time, including the equilibrium and instantaneous moduli and the 

peak in the phase angle of the complex modulus. By performing a length scale study 

and comparing the experimental results to theoretical predictions, we confirm that the 

mechanism underlying the observed dynamic nanomechanics is due to solid
fluid 

interactions (poroelasticity) at the molecular scale. Utilizing finite element modeling, the molecular-scale hydraulic permeability of the aggrecan assembly was quantified (kaggrecan = (4.8 ( 2.8) 10
15 m4 

/N 3 s) and found to be similar to the nanoscale hydraulic permeability of intact normal cartilage tissue 

but much lower than that of early diseased tissue. The mechanisms underlying aggrecan poroelasticity were further investigated by altering electrostatic 

interactions between the molecule's constituent glycosaminoglycan chains: electrostatic interactions dominated steric interactions in governing molecular 

behavior. While the hydraulic permeability of aggrecan layers does not change across species and age, aggrecan from adult human cartilage is stiffer than 

the aggrecan from newborn human tissue.},

keywords = {Experimentation, Fabrication, Nanoscale video imaging for dynamic process visualization, Nanotechnology, Physical System Modeling},

pubstate = {published},

tppubtype = {article}

}

@article{MRL_AFM_Multi_PI_control,

title = {Multi-actuation and PI control: A simple recipe for high-speed and large-range atomic force microscopy},

author = {Iman Soltani Bozchalooi and Kamal Youcef-Toumi},

url = {http://www.sciencedirect.com/science/article/pii/S0304399114001491},

doi = {https://doi.org/10.1016/j.ultramic.2014.07.010},

issn = {0304-3991},

year  = {2014},

date = {2014-01-01},

journal = {Ültramicroscopy},

volume = {146},

pages = {117 - 124},

abstract = {High speed atomic force microscopy enables observation of dynamic nano-scale processes. However, maintaining a minimal interaction force between the sample and the probe is challenging at high speed specially when using conventional piezo-tubes. While rigid AFM scanners are operational at high speeds with the drawback of reduced tracking range, multi-actuation schemes have shown potential for high-speed and large-range imaging. Here we present a method to seamlessly incorporate additional actuators into conventional AFMs. The equivalent behavior of the resulting multi-actuated setup resembles that of a single high-speed and large-range actuator with maximally flat frequency response. To achieve this, the dynamics of the individual actuators and their couplings are treated through a simple control scheme. Upon the implementation of the proposed technique, commonly used PI controllers are able to meet the requirements of high-speed imaging. This forms an ideal platform for retroactive enhancement of existing AFMs with minimal cost and without compromise on the tracking range. A conventional AFM with tube scanner is retroactively enhanced through the proposed method and shows an order of magnitude improvement in closed loop bandwidth performance while maintaining large range. The effectiveness of the method is demonstrated on various types of samples imaged in contact and tapping modes, in air and in liquid.},

keywords = {Control Theory, Experimentation, Instrumentation, Nanoscale video imaging for dynamic process visualization, Nanotechnology, Physical System Modeling, Simulation},

pubstate = {published},

tppubtype = {article}

}

@article{MRL_AFM_Cartilage_Early_Impairment,

title = {High-Bandwidth AFM-Based Rheology Reveals that Cartilage is Most Sensitive to High Loading Rates at Early Stages of Impairment},

author = {Hadi Nia and Iman Soltani and Yang Li and Lin Han and Han-Hwa Hung and Eliot Frank and Kamal Youcef-Toumi and Christine Ortiz and Alan Grodzinsky},

url = {https://dspace.mit.edu/handle/1721.1/92000},

doi = {10.1016/j.bpj.2013.02.048},

issn = {00063496},

year  = {2013},

date = {2013-04-02},

journal = {Biophysical journal},

volume = {104},

pages = {1529-37},

publisher = {Elsevier B.V},

abstract = {Utilizing a newly developed atomic-force-microscopy-based wide-frequency rheology system, we measured the dynamic nanomechanical behavior of normal and glycosaminoglycan (GAG)-depleted cartilage, the latter representing matrix degradation that occurs at the earliest stages of osteoarthritis. We observed unique variations in the frequency-dependent stiffness and hydraulic permeability of cartilage in the 1 Hz-to-10 kHz range, a frequency range that is relevant to joint motions from normal ambulation to high-frequency impact loading. Measurement in this frequency range is well beyond the capabilities of typical commercial atomic force microscopes. We showed that the dynamic modulus of cartilage undergoes a dramatic alteration after GAG loss, even with the collagen network still intact: whereas the magnitude of the dynamic modulus decreased two- to threefold at higher frequencies, the peak frequency of the phase angle of the modulus (representing fluid-solid frictional dissipation) increased 15-fold from 55 Hz in normal cartilage to 800 Hz after GAG depletion. These results, based on a fibril-reinforced poroelastic finite-element model, demonstrated that GAG loss caused a dramatic increase in cartilage hydraulic permeability (up to 25-fold), suggesting that early osteoarthritic cartilage is more vulnerable to higher loading rates than to the conventionally studied “loading magnitude”. Thus, over the wide frequency range of joint motion during daily activities, hydraulic permeability appears the most sensitive marker of early tissue degradation.},

keywords = {Nanoscale video imaging for dynamic process visualization, Nanotechnology, Physical System Modeling, Visualization},

pubstate = {published},

tppubtype = {article}

}