Scanning Probe Microscopy
Probe Based Lithography
Probe based lithography involves creating nanometer sized features from photoresist and metal on conducting and semiconducting substrates. Near field optical, electrical and thermal fields are employed in combination with evaporation, etching and electroplating to provide high-speed alternatives for mask-less nanofabrication.
Nanopositioning
A nanopositioner is a electromechanical device for moving objects in three dimensions with atomic, or sub-atomic resolution. Nanopositioners are employed in applications such as imaging, fabrication and optics. This field encompasses mechanical design, sensor design, and control theory. More details.
Electroactive Optics
Piezoelectric actuators can be combined with mirrors, lenses and objectives to actively control the path and properties of an optical field or laser beam. High speed electro-optics are required for precision lasers, maskless lithography, and microscopy.
Precision Sensors
This project aims to study the fundamental limitations of capacitive, optical and magnetic position sensors. New techniques are under development to provide sub-atomic resolution over extremely wide bandwidth.
Biomedical Devices
An endoscopic pill robot is being developed for noninvasive imaging and intervention. The robot can be swallowed and includes power transmission, 6-Dimensional localization, and locomotion.
Piezo Actuators and Amplifiers
Piezo Robotics
Due to their compact size and high efficiency, piezoelectric actuators are ideal for micro-actuation in bio-inspired robotics. This project is developing actuators and mechanics for a piezoelectric dragon-fly robot.
Ruppert, M. G.; de Bem, N. F. S.; Fleming, A. J.; Yong, Y. K.
Characterization of Active Microcantilevers Using Laser Doppler Vibrometry Book Chapter
In: Vibration Engineering for a Sustainable Future , Chapter 45, Springer, 2021, ISBN: 978-3-030-48153-7.
@inbook{Ruppert2021b,
title = {Characterization of Active Microcantilevers Using Laser Doppler Vibrometry},
author = {M. G. Ruppert and N. F. S. de Bem and A. J. Fleming and Y. K. Yong},
url = {https://www.precisionmechatronicslab.com/wp-content/uploads/2022/03/BC21a.pdf},
doi = {10.1007/978-3-030-48153-7},
isbn = {978-3-030-48153-7},
year = {2021},
date = {2021-06-18},
urldate = {2021-06-18},
booktitle = {Vibration Engineering for a Sustainable Future
},
issuetitle = {Experiments, Materials and Signal Processing, Vol. 2},
publisher = {Springer},
chapter = {45},
abstract = {Active atomic force microscope cantilevers with on-chip actuation and sensing provide several advantages over passive cantilevers which rely on piezoacoustic base-excitation and the optical beam deflection measurement. Most importantly, these cantilevers provide clean frequency responses, the possibility of down-scaling and parallelization to cantilever arrays as well as the absence of optical interferences. In this paper, we demonstrate the analysis and calibration steps for three active cantilever geometries with integrated piezoelectric actuation. For this purpose, laser Doppler vibrometry (LDV) is used to experimentally obtain the deflection mode shapes of the first three eigenmodes, calibrate actuation gains, and to determine the dynamic modal stiffnesses using the Brownian spectrum of the cantilever. The experimental values are compared with finite element simulations.},
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}
Xavier, M. S.; Fleming, A. J.; Yong, Y. K.
Design and Control of Pneumatic Systems for Soft Robotics: a Simulation Approach Journal Article
In: IEEE Robotics and Automation Letters, vol. 6, iss. 3, pp. 5800-5807, 2021, ISSN: 2377-3766.
@article{J21d,
title = {Design and Control of Pneumatic Systems for Soft Robotics: a Simulation Approach},
author = {M. S. Xavier and A. J. Fleming and Y. K. Yong},
url = {https://www.precisionmechatronicslab.com/wp-content/uploads/2022/03/J21d.pdf},
doi = {10.1109/LRA.2021.3086425},
issn = {2377-3766},
year = {2021},
date = {2021-06-04},
urldate = {2021-06-04},
journal = {IEEE Robotics and Automation Letters},
volume = {6},
issue = {3},
pages = {5800-5807},
abstract = {Pressure control plays a major role in the overall performance of fluid-driven soft robots. Due to the increasing demand for higher speed actuation and precision, a need exists for a practical design methodology that converts actuator performance specifications to a set of minimum pneumatic specifications, such as receiver volume and pressure, and valve conductance. This article presents a systematic parameter selection approach for pneumatic soft robotic systems by taking into consideration the desired closed-loop pressure responses. The two controllers under evaluation here are the PI controller with anti-windup and the on-off controller with hysteresis. Simulations are developed within Simscape Fluids to evaluate the effect of physical components and controller parameters on the actuator performance. The proposed parameter selection procedures are then applied on three soft actuators and their closed-loop pressure responses are experimentally evaluated. The measured pressure responses are in close agreement with the simulations and satisfy the rise time specifications.},
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Seethaler, R.; Mansour, S. Z.; Ruppert, M. G.; Fleming, A. J.
Position and force sensing using strain gauges integrated into piezoelectric bender electrodes Journal Article
In: Sensors and Actuators A: Physical, vol. 321, pp. 112416, 2021, ISBN: 0924-4247.
@article{J21e,
title = {Position and force sensing using strain gauges integrated into piezoelectric bender electrodes},
author = {R. Seethaler and S. Z. Mansour and M. G. Ruppert and A. J. Fleming},
url = {https://www.precisionmechatronicslab.com/wp-content/uploads/2022/03/J21e-1.pdf},
doi = {10.1016/j.sna.2020.112416},
isbn = {0924-4247},
year = {2021},
date = {2021-04-15},
urldate = {2020-12-30},
journal = {Sensors and Actuators A: Physical},
volume = {321},
pages = {112416},
abstract = {This article derives design guidelines for integrating strain gauges into the electrodes of piezoelectric bending actuators. The proposed sensor can estimate the actuator tip displacement in response to an applied voltage and an external applied tip force. The actuator load force is also estimated with an accuracy of 8% full scale by approximating the actuator response with a linear model. The applications of this work include micro-grippers and pneumatic valves, which both require the measurement of deflection and load force. At present, this is achieved by external sensors. However, this work shows that these functions can be integrated into the actuator electrodes.},
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Moore, S. I.; Yong, Y. K.; Omidbeike, M.; Fleming, A. J.
Serial-kinematic monolithic nanopositioner with in-plane bender actuators Journal Article
In: Mechatronics, vol. 75, no. 102541, 2021, ISBN: 0957-4158.
@article{Moore2021,
title = {Serial-kinematic monolithic nanopositioner with in-plane bender actuators},
author = {S. I. Moore and Y. K. Yong and M. Omidbeike and A. J. Fleming},
url = {https://www.precisionmechatronicslab.com/wp-content/uploads/2021/03/J21c.pdf},
doi = {https://doi.org/10.1016/j.mechatronics.2021.102541},
isbn = {0957-4158},
year = {2021},
date = {2021-03-23},
journal = {Mechatronics},
volume = {75},
number = {102541},
abstract = {This article describes a monolithic nanopositioner constructed from in-plane bending actuators which provide greater deflection than previously reported extension actuators, at the expense of stiffness and resonance frequency. The proposed actuators are demonstrated by constructing an XY nanopositioning stage with a serial kinematic design. Analytical modeling and finite-element-analysis accurately predicts the experimental performance of the nanopositioner. A 10μm range is achieved in the X and Y axes with an applied voltage of +/-200 V. The first resonance mode occurs at 250 Hz in the Z axis. The stage is demonstrated for atomic force microscopy imaging.},
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pubstate = {published},
tppubtype = {article}
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Xavier, M. S.; Fleming, A. J.; Yong, Y. K.
Finite Element Modeling of Soft Fluidic Actuators: Overview and Recent Developments Journal Article
In: Advanced Intelligent Systems, vol. 3, no. 2, pp. 2000187, 2021, ISBN: 2640-4567.
@article{J21b,
title = {Finite Element Modeling of Soft Fluidic Actuators: Overview and Recent Developments},
author = {M. S. Xavier and A. J. Fleming and Y. K. Yong},
url = {https://www.precisionmechatronicslab.com/wp-content/uploads/2021/02/J21b.pdf},
doi = {10.1002/aisy.202000187},
isbn = {2640-4567},
year = {2021},
date = {2021-02-01},
journal = {Advanced Intelligent Systems},
volume = {3},
number = {2},
pages = {2000187},
abstract = {Many soft robots are composed of soft fluidic actuators that are fabricated from silicone rubbers and use hydraulic or pneumatic actuation. The strong nonlinearities and complex geometries of soft actuators hinder the development of analytical models to describe their motion. Finite element modeling provides an effective solution to this issue and allows the user to predict performance and optimize soft actuator designs. Herein, the literature on a finite element analysis of soft actuators is reviewed. First, the required nonlinear elasticity concepts are introduced with a focus on the relevant models for soft robotics. In particular, the procedure for determining material constants for the hyperelastic models from material testing and curve fitting is explored. Then, a comprehensive review of constitutive model parameters for the most widely used silicone rubbers in the literature is provided. An overview of the procedure is provided for three commercially available software packages (Abaqus, Ansys, and COMSOL). The combination of modeling procedures, material properties, and design guidelines presented in this article can be used as a starting point for soft robotic actuator design.},
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pubstate = {published},
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}