Publications

@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 = {https://www.precisionmechatronicslab.com/wp-content/uploads/2021/01/J21a.pdf},

doi = {10.1016/j.sna.2020.112519},

issn = {0924-4247},

year  = {2021},

date = {2021-01-19},

urldate = {2021-01-19},

journal = {Sensors & Actuators: A. Physical},

volume = {319},

pages = {112519},

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 = {AFM, Cantilever, MEMS, Sensors, Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{Moore2020,

title = {AFM Cantilever Design for Multimode Q Control: Arbitrary Placement of Higher-Order Modes},

author = {S. I. Moore and M. G. Ruppert and Y. K. Yong},

url = {https://ieeexplore.ieee.org/document/9006926},

doi = {10.1109/TMECH.2020.2975627},

year  = {2020},

date = {2020-02-21},

journal = { IEEE/ASME Transactions on Mechatronics},

pages = {1-6},

abstract = {In the fast growing field of multifrequency atomic force microscopy (AFM), the benefits of using higher-order modes has been extensively reported on. However, higher modes of AFM cantilevers are difficult to instrument and Q control is challenging owing to their high frequency nature. At these high frequencies, the latencies in the computations and analog conversions of digital signal processing platforms become significant and limit the effective bandwidth of digital feedback controller implementations. To address this issue, this article presents a novel cantilever design for which the first five modes are placed within a 200 kHz bandwidth. The proposed cantilever is designed using a structural optimization routine. The close spacing and low mechanical bandwidth of the resulting cantilever allows for the implementation of Q controllers for all five modes using a standard FPGA development board for bimodal AFM and imaging on higher-order modes.},

note = {Early Access},

keywords = {AFM, Cantilever, MEMS, Multifrequency AFM, Smart Structures, SPM, Vibration Control},

pubstate = {published},

tppubtype = {article}

}

@article{Moore2019c,

title = {An optimization framework for the design of piezoelectric AFM cantilevers},

author = {S. I. Moore and M. G. Ruppert and Y. K. Yong},

url = {https://www.sciencedirect.com/science/article/pii/S0141635919302260},

year  = {2019},

date = {2019-08-15},

journal = {Precision Engineering},

volume = {60},

pages = {130-142},

abstract = {To facilitate further miniaturization of atomic force microscopy (AFM) cantilevers and to eliminate the standard optical beam deflection sensor, integrated piezoelectric actuation and sensing on the chip level is a promising option. This article presents a topology optimization method for dynamic mode AFM cantilevers that maximizes the sensitivity of an integrated piezoelectric sensor under stiffness and resonance frequency constraints. Included in the formulation is a new material model C-SIMP (connectivity and solid isotropic material with penalization) that extends the SIMP model to explicitly include the penalization of unconnected structures. Example cantilever designs demonstrate the potential of the topology optimization method. The results show, firstly, the C-SIMP material model significantly reduces connectivity issues and, secondly, arbitrary cantilever topologies can produce increases in sensor sensitivity or resonance frequency compared to a rectangular topology.},

keywords = {AFM, Cantilever, MEMS, Piezoelectric Transducers and Drives, Smart Structures, SPM},

pubstate = {published},

tppubtype = {article}

}

@article{Ruppert2018b,

title = {Multimodal atomic force microscopy with optimized higher eigenmode sensitivity using on-chip piezoelectric actuation and sensing},

author = {M. G. Ruppert and S. I. Moore and M. Zawierta and A. J. Fleming and G. Putrino and Y. K. Yong},

url = {https://www.precisionmechatronicslab.com/wp-content/uploads/2019/08/Ruppert_2019_Nanotechnology_30_085503.pdf},

doi = {https://doi.org/10.1088/1361-6528/aae40b},

year  = {2019},

date = {2019-01-02},

journal = {Nanotechnology},

volume = {30},

number = {8},

pages = {085503},

abstract = {Atomic force microscope (AFM) cantilevers with integrated actuation and sensing provide several distinct advantages over conventional cantilever instrumentation. These include clean frequency responses, the possibility of down-scaling and parallelization to cantilever arrays as well as the absence of optical interference. While cantilever microfabrication technology has continuously advanced over the years, the overall design has remained largely unchanged; a passive rectangular shaped cantilever design has been adopted as the industry wide standard. In this article, we demonstrate multimode AFM imaging on higher eigenmodes as well as bimodal AFM imaging with cantilevers using fully integrated piezoelectric actuation and sensing. The cantilever design maximizes the higher eigenmode deflection sensitivity by optimizing the transducer layout according to the strain mode shape. Without the need for feedthrough cancellation, the read-out method achieves close to zero actuator/sensor feedthrough and the sensitivity is sufficient to resolve the cantilever Brownian motion.},

keywords = {AFM, Cantilever, MEMS, Multifrequency AFM, Piezoelectric Transducers and Drives, Sensors, Smart Structures, SPM},

pubstate = {published},

tppubtype = {article}

}

@article{Ruppert2018b,

title = {Self-sensing, estimation and control in multifrequency Atomic Force Microscopy. },

author = {M. G. Ruppert},

url = {https://royalsoc.org.au/images/pdf/journal/151-1-Ruppert.pdf},

issn = {0035-9173/18/010111-01},

year  = {2018},

date = {2018-06-01},

journal = {Journal & Proceedings of the Royal Society of New South Wales},

volume = {151},

number = {1},

pages = {111},

abstract = {Despite the undeniable success of the atomic force  microscope  (AFM),  dynamic  techniques still face limitations in terms of spatial resolution, imaging speed and high cost of acquisition. In order to expand the capabilities  of  the  instrument,  it  was  realized  that the information about the nano-mechanical properties  of  a  sample  are  encoded  over  a range of frequencies and the excitation and detection of higher-order eigenmodes of the micro-cantilever  open  up  further  informa-

tion  channels.  The  ability  to  control  these modes and their fast responses to excitation is believed to be the key to unravelling the true potential of these ethods. This work addresses  three  major  drawbacks  of  the standard AFM setup, which limit the feasibility of multi-frequency approaches.



First,   microelectromechanical   system (MEMS)  probes  with  integrated  piezoelectric layers is motivated, enabling the development of novel multimode self-sensing and self-actuating techniques. Specifically, these piezoelectric  transduction  schemes  permit the  miniaturization  of  the  entire  AFM towards  a  cost-effective  single-chip  device with nanoscale precision in a much smaller form factor than that of conventional macroscale instruments.



Second, the integrated actuation enables the development of multimode controllers which  exhibits  remarkable  performance  in arbitrarily  modifying  the  quality  factor  of multiple eigenmodes and comes with inherent  stability  robustness.  The  experimental results  demonstrate  improved  imaging  stability,  higher  scan  speeds  and  adjustable contrast  when  mapping  nano-mechanical properties of soft samples. 



Last, in light of the demand for constantly increasing  imaging  speeds  while  providing multi-frequency flexibility, the estimation of multiple components of the high-frequency deflection signal is performed with a linear time-varying multi-frequency Kalman filter. The chosen representation allows for an efficient high-bandwidth implementation on a Field  Programmable  Gate  Array. Tracking bandwidth, noise performance and trimodal AFM imaging on a two-component polymer sample  are  verified  and  shown  to  be  superior to that of the commonly used lock-in amplifier.},

keywords = {Cantilever, MEMS, Multifrequency AFM, Sensors, Smart Structures, SPM, System Identification, Vibration Control},

pubstate = {published},

tppubtype = {article}

}

@article{Ruppert2017,

title = {On-chip Dynamic Mode Atomic Force Microscopy: A silicon-on-insulator MEMS approach},

author = {M. G. Ruppert and A. G. Fowler and M. Maroufi and S. O. R. Moheimani},

doi = {10.1109/JMEMS.2016.2628890},

year  = {2017},

date = {2017-02-01},

journal = {IEEE Journal of Microelectromechanical Systems},

volume = {26},

number = {1},

pages = {215-225},

abstract = {The atomic force microscope (AFM) is an invaluable scientific tool; however, its conventional implementation as a relatively costly macroscale system is a barrier to its more widespread use. A microelectromechanical systems (MEMS) approach to AFM design has the potential to significantly reduce the cost and complexity of the AFM, expanding its utility beyond current applications. This paper presents an on-chip AFM based on a silicon-on-insulator MEMS fabrication process. The device features integrated xy electrostatic actuators and electrothermal sensors as well as an AlN piezoelectric layer for out-of-plane actuation and integrated deflection sensing of a microcantilever. The three-degree-of-freedom design allows the probe scanner to obtain topographic tapping-mode AFM images with an imaging range of up to 8μm x 8μm in closed loop.},

keywords = {MEMS, Nanopositioning, Piezoelectric Transducers and Drives, Sensors, Smart Structures, SPM, Tracking Control},

pubstate = {published},

tppubtype = {article}

}

@article{J15c,

title = {Optimal integral force feedback for active vibration control},

author = {Y. R. Teo and A. J. Fleming},

url = {https://www.precisionmechatronicslab.com/wp-content/uploads/2015/10/J15c.pdf},

year  = {2015},

date = {2015-06-27},

journal = {Journal of Sound and Vibration},

volume = {356},

number = {11},

pages = {20-33},

abstract = {This paper proposes an improvement to Integral Force Feedback (IFF), which is a popular method for active vibration control for structures and mechanical systems. Benefits of IFF includes robustness, guaranteed stability and simplicity. However, the maximum damping performance is dependent on the stiffness of the system; hence, some systems cannot be adequately controlled. In this paper, an improvement to the classical force feedback control scheme is proposed. The improved method achieves arbitrary damping for any mechanical system by introducing a feed-through term. The proposed improvement is experimentally demonstrated by actively damping an objective lens assembly for a high-speed confocal microscope.},

keywords = {Nanopositioning, Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{Ruppert2013b,

title = {A novel self-sensing technique for tapping-mode atomic force microscopy},

author = {M. G. Ruppert and S. O. R. Moheimani},

doi = {http://dx.doi.org/10.1063/1.4841855},

year  = {2013},

date = {2013-12-01},

journal = {Review of Scientific Instruments},

volume = {84},

number = {12},

pages = {125006},

abstract = {This work proposes a novel self-sensing tapping-mode atomic force microscopy operation utilizing charge measurement. A microcantilever coated with a single piezoelectric layer is simultaneously used for actuation and deflection sensing. The cantilever can be batch fabricated with existing Micro Electro Mechanical System processes. The setup enables the omission of the optical beam deflection technique which is commonly used to measure the cantilever oscillation amplitude. Due to the high amount of capacitive feedthrough in the measured charge signal, a feedforward control technique is employed to increase the dynamic range from less than 1dB to approximately 35dB. Experiments show that the conditioned charge signal achieves excellent signal-to-noise ratio and can therefore be used as a feedback signal for AFM imaging.},

keywords = {MEMS, Smart Structures, SPM, System Identification},

pubstate = {published},

tppubtype = {article}

}

@article{J08b,

title = {Model predictive control applied to constraint handling in active noise and vibration control},

author = {A. G. Wills and D. Bates and A. J. Fleming and B. Ninness and S. O. R. Moheimani},

url = {https://www.precisionmechatronicslab.com/wp-content/publications/J08b.pdf},

year  = {2008},

date = {2008-12-01},

journal = {IEEE Transactions on Control Systems Technology},

volume = {16},

number = {1},

pages = {3--12},

keywords = {Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{J07a,

title = {Integral resonant control of collocated smart structures},

author = {S. S. Aphale and A. J. Fleming and S. O. R. Moheimani},

url = {https://www.precisionmechatronicslab.com/wp-content/publications/J07a.pdf},

year  = {2007},

date = {2007-12-01},

journal = {IOP Smart materials and Structures},

volume = {16},

pages = {439-446},

keywords = {Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{J05c,

title = {Control oriented synthesis of high performance piezoelectric shunt impedances for structural vibration control},

author = {A. J. Fleming and S. O. R. Moheimani},

url = {https://www.precisionmechatronicslab.com/wp-content/publications/J05c.pdf},

year  = {2005},

date = {2005-12-01},

journal = {IEEE Transactions on Control Systems Technology},

volume = {13},

number = {1},

pages = {98--112},

keywords = {Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{J04b,

title = {Adaptive multimode resonant piezoelectric shunt damping},

author = {D. Niederberger and A. J. Fleming and S. O. R. Moheimani and M. Morari},

url = {https://www.precisionmechatronicslab.com/wp-content/publications/J04b.pdf},

year  = {2004},

date = {2004-12-01},

journal = {IOP Smart Materials and Structures},

volume = {18},

number = {2},

pages = {291--315},

keywords = {Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{J04a,

title = {Dynamics, Stability and Control of Multivariable Piezoelectric Shunts},

author = {S. O. R. Moheimani and A. J. Fleming and S. Behrens},

url = {https://www.precisionmechatronicslab.com/wp-content/publications/J04a.pdf},

year  = {2004},

date = {2004-01-01},

journal = {IEEE/ASME Transactions on Mechatronics},

volume = {9},

number = {1},

pages = {87--99},

keywords = {Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{J03b,

title = {Adaptive piezoelectric shunt damping},

author = {A. J. Fleming and S. O. R. Moheimani},

url = {https://www.precisionmechatronicslab.com/wp-content/publications/J03b.pdf},

year  = {2003},

date = {2003-01-01},

journal = {IOP Smart Materials and Structures},

volume = {12},

number = {1},

pages = {18--28},

keywords = {Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{J03a,

title = {A broadband controller for shunt piezoelectric damping of structural vibration},

author = {S. Behrens and A. J. Fleming and S. O. R. Moheimani},

url = {https://www.precisionmechatronicslab.com/wp-content/publications/J03a.pdf},

year  = {2003},

date = {2003-01-01},

journal = {IOP Smart Materials and Structures},

volume = {12},

number = {1},

pages = {36--48},

keywords = {Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{J03c,

title = {Reducing the Inductance Requirements of Piezoelectric Shunt Damping Circuits},

author = {A. J. Fleming and S. O. R. Moheimani and S. Behrens},

url = {https://www.precisionmechatronicslab.com/wp-content/publications/J03c.pdf},

year  = {2003},

date = {2003-01-01},

journal = {IOP Smart Materials and Structures},

volume = {12},

number = {1},

pages = {57--64},

keywords = {Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{J03f,

title = {Multiple mode current flowing passive piezoelectric shunt controller},

author = {S. Behrens and S. O. R. Moheimani and A. J. Fleming},

url = {https://www.precisionmechatronicslab.com/wp-content/publications/J03f.pdf},

year  = {2003},

date = {2003-01-01},

journal = {Journal of Sound and Vibration},

volume = {266},

number = {5},

pages = {929--942},

keywords = {Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{J03d,

title = {On the feedback structure of wideband piezoelectric shunt damping systems},

author = {S. O. R. Moheimani and A. J. Fleming and S. Behrens},

url = {https://www.precisionmechatronicslab.com/wp-content/publications/J03d.pdf},

year  = {2003},

date = {2003-01-01},

journal = {IOP Smart Materials and Structures},

volume = {12},

number = {1},

pages = {49--56},

keywords = {Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{J02a,

title = {Optimization and implementation of multi-mode piezoelectric shunt damping systems},

author = {A. J. Fleming and S. Behrens and S. O. R. Moheimani},

url = {https://www.precisionmechatronicslab.com/wp-content/publications/J02a.pdf},

year  = {2002},

date = {2002-01-01},

journal = {IEEE/ASME Transactions on Mechatronics},

volume = {7},

number = {1},

pages = {87--94},

keywords = {Smart Structures},

pubstate = {published},

tppubtype = {article}

}

@article{J01a,

title = {Highly resonant controller for multimode piezoelectric shunt damping},

author = {S. O. R. Moheimani and A. J. Fleming and S. Behrens},

url = {https://www.precisionmechatronicslab.com/wp-content/publications/J01a.pdf},

year  = {2001},

date = {2001-01-01},

journal = {IEE Electronics Letters},

volume = {37},

number = {25},

pages = {1505--1506},

keywords = {Smart Structures},

pubstate = {published},

tppubtype = {article}

}