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 bender actuator with integrated 200V power electronics
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.
Moore, S I; Yong, Y K; Omidbeike, M; Fleming, A J Serial-kinematic monolithic nanopositioner with in-plane bender actuators Journal Article In: Mechatronics, 75 (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 = {http://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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. ![]() |
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, 3 (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 = {http://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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. ![]() |
Ruppert, M G; Fleming, A J; Yong, Y K Active atomic force microscope cantilevers with integrated device layer piezoresistive sensors Journal Article In: Sensors & Actuators: A. Physical, 2021. @article{Ruppert2021, title = {Active atomic force microscope cantilevers with integrated device layer piezoresistive sensors}, author = {M. G. Ruppert and A. J. Fleming and Y. K. Yong}, url = {http://www.precisionmechatronicslab.com/wp-content/uploads/2021/01/J21a.pdf}, doi = {10.1016/j.sna.2020.112519}, year = {2021}, date = {2021-01-19}, journal = {Sensors & Actuators: A. Physical}, 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 optical beam deflection measurement. Active microcantilevers exhibit a clean frequency response, provide a path-way to miniturization and parallelization and avoid the need for optical alignment. However, active microcantilevers are presently limited by the feedthrough between actuators and sensors, and by the cost associated with custom microfabrication. In this work, we propose a hybrid cantilever design with integrated piezoelectric actuators and a piezoresistive sensor fabricated from the silicon device layer without requiring an additional doping step. As a result, the design can be fabricated using a commercial five-mask microelectromechanical systems fabrication process. The theoretical piezoresistor sensitivity is compared with finite element simulations and experimental results obtained from a prototype device. The proposed approach is demonstrated to be a promising alternative to conventional microcantilever actuation and deflection sensing}, keywords = {}, pubstate = {published}, tppubtype = {article} } Active atomic force microscope cantilevers with on-chip actuation and sensing provide several advantages over passive cantilevers which rely on piezoacoustic base-excitation and optical beam deflection measurement. Active microcantilevers exhibit a clean frequency response, provide a path-way to miniturization and parallelization and avoid the need for optical alignment. However, active microcantilevers are presently limited by the feedthrough between actuators and sensors, and by the cost associated with custom microfabrication. In this work, we propose a hybrid cantilever design with integrated piezoelectric actuators and a piezoresistive sensor fabricated from the silicon device layer without requiring an additional doping step. As a result, the design can be fabricated using a commercial five-mask microelectromechanical systems fabrication process. The theoretical piezoresistor sensitivity is compared with finite element simulations and experimental results obtained from a prototype device. The proposed approach is demonstrated to be a promising alternative to conventional microcantilever actuation and deflection sensing ![]() |
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, pp. 112416, 2020, ISBN: 0924-4247. @article{J20h, 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 = {http://www.precisionmechatronicslab.com/wp-content/uploads/2021/01/J20h-prepress-2.pdf}, doi = {10.1016/j.sna.2020.112416}, isbn = {0924-4247}, year = {2020}, date = {2020-12-30}, journal = {Sensors and Actuators A: Physical}, 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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. ![]() |
de Bem, N F S; Ruppert, M G; Yong, Y K; Fleming, A J Integrated force and displacement sensing in active microcantilevers for off-resonance tapping mode atomic force microscopy Inproceedings In: International Conference on Manipulation, Automation and Robotics at Small Scales (MARSS), pp. 1-6, 2020. @inproceedings{C20c, title = {Integrated force and displacement sensing in active microcantilevers for off-resonance tapping mode atomic force microscopy}, author = {N. F. S. de Bem and M. G. Ruppert and Y. K. Yong and A. J. Fleming}, url = {http://www.precisionmechatronicslab.com/wp-content/uploads/2021/01/C20c.pdf}, doi = {10.1109/MARSS49294.2020.9307881}, year = {2020}, date = {2020-11-30}, booktitle = {International Conference on Manipulation, Automation and Robotics at Small Scales (MARSS)}, pages = {1-6}, abstract = {Integrated on-chip actuation and sensing in microcantilevers for atomic force microscopy (AFM) allows faster scanning speeds, cleaner frequency responses and smaller cantilevers. However, a single integrated sensor suffers from crosscoupling between displacements originating from tip-sample forces and direct actuation. This paper addresses this issue by presenting a novel microcantilever with on-chip actuation and integrated dual sensing for AFM with application to offresonance tapping modes in AFM. The proposed system is able to measure tip force and deflection simultaneously. A mathematical model is developed for a rectangular cantilever to describe the system and is validated with finite element analysis.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Integrated on-chip actuation and sensing in microcantilevers for atomic force microscopy (AFM) allows faster scanning speeds, cleaner frequency responses and smaller cantilevers. However, a single integrated sensor suffers from crosscoupling between displacements originating from tip-sample forces and direct actuation. This paper addresses this issue by presenting a novel microcantilever with on-chip actuation and integrated dual sensing for AFM with application to offresonance tapping modes in AFM. The proposed system is able to measure tip force and deflection simultaneously. A mathematical model is developed for a rectangular cantilever to describe the system and is validated with finite element analysis. ![]() |