Fangzhou Xia

@article{2023IEEETM,

title = {AFM SMILER: A Scale Model Interactive Learning Extended Reality Toolkit for Atomic Force Microscopy based on Digital Twin Technology},

author = {Fangzhou Xia* and Shane Lovet and Eyan Forsythe and Malek Ibrahim and Kamal Youcef-Toumi},

url = {https://ieeexplore.ieee.org/abstract/document/10136835},

doi = {10.1109/TMECH.2023.3274695},

year  = {2023},

date = {2023-06-01},

urldate = {2023-01-01},

journal = {IEEE Transactions on Mechatronics (in preparation)},

abstract = {Atomic force microscope (AFM) is a precision mechatronic system for nanoscale imaging of surfaces. Due to limited instrument access and lack of visualization techniques, understanding its principles can be challenging. Digital twin technology allows the creation of virtual representations of physical systems, which can be particularly useful to address challenges in AFM education. To realistically simulate nanoscale physics, we first developed new efficient algorithms for four virtual scale models, including cantilever mechanics, probe transducers, controller tuning, and contact mechanics. Second, three simulated experiment interactive learning modules are developed for instrument operation, including virtual imaging, system overview, and imaging modalities. In the end, three hardware systems are integrated for an extended reality experience, including a macroscopic AFM scale model, a haptic device for probe-sample interaction force feedback and an upgraded low-cost educational AFM for nanoscale imaging and instrumentation. This completes the eight total modules for the AFM SMILER: A Scale Model Interactive Learning Extended Reality toolkit. Preliminary studies shows the toolkit being helpful for AFM education. In addition to mechatronics and nanotechnology education, techniques developed in this work can be generally applied to computationally efficient realistic digital twin creation.},

keywords = {Atomic Force Microscopy, Design, Education, Experimentation, Instrumentation, Intelligence, Mechatronics, MEMS, Modeling & Simulation, Nanorobotics, Sensor, Theory},

pubstate = {published},

tppubtype = {article}

}

@article{2022MDPIBiosensors,

title = {Review: Advanced Atomic Force Microscopy for Biomedical Research},

author = {Fangzhou Xia* and Kamal Youcef-Toumi},

url = {https://www.mdpi.com/2079-6374/12/12/1116},

year  = {2022},

date = {2022-01-01},

urldate = {2022-01-01},

journal = {Biosensors},

volume = {12},

number = {12},

pages = {1116},

publisher = {MDPI},

abstract = {Visualization of biomedical samples in their native environments at the microscopic scale is crucial for studying fundamental principles and discovering biomedical systems with complex interaction. The study of dynamic biological processes requires a microscope system with multiple modalities, high spatial/temporal resolution, large imaging ranges, versatile imaging environments and ideally in-situ manipulation capabilities. Recent development of new Atomic Force Microscopy (AFM) capabilities has made it such a powerful tool for biological and biomedical research. This review introduces novel AFM functionalities including high-speed imaging for dynamic process visualization, mechanobiology with force spectroscopy, molecular species characterization, and AFM nano-manipulation. These capabilities enable many new possibilities for novel scientific research and allow scientists to observe and explore processes at the nanoscale like never before. Selected application examples from recent studies are provided to demonstrate the effectiveness of these AFM techniques.},

keywords = {Atomic Force Microscopy, Instrumentation, Medication, MEMS, Nanorobotics, Review},

pubstate = {published},

tppubtype = {article}

}

@article{2021Mechatronics,

title = {A Modular Low-cost Atomic Force Microscope for Precision Mechatronics Education},

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

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

issn = {0957-4158},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Mechatronics},

volume = {76},

pages = {102550},

publisher = {Elsevier},

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 = {Atomic Force Microscopy, Design, Education, Experimentation, Instrumentation, Mechatronics, Nanorobotics, Signal Processing},

pubstate = {published},

tppubtype = {article}

}

@article{2019NM,

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.mdpi.com/2079-4991/9/7/1013},

year  = {2019},

date = {2019-01-01},

urldate = {2019-01-01},

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 = {Atomic Force Microscopy, Experimentation, Instrumentation, Material Science, Mechatronics, MEMS, Nanorobotics, Sensor},

pubstate = {published},

tppubtype = {article}

}

@article{2017JVST,

title = {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 S Bozchalooi and Fangzhou Xia* and Kamal Youcef-Toumi and Mathias Holz and Alexander Reum},

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

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

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

volume = {35},

number = {6},

pages = {06G101},

publisher = {AVS},

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 carried out 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 = {Actuator, Atomic Force Microscopy, Instrumentation, MEMS, Nanorobotics, Review, Sensor},

pubstate = {published},

tppubtype = {article}

}