This paper proposes an innovative virtual chain-based kinematic calibration for the 4PPa-2PaR parallel manipulators with subchain architectures. Conventional calibration methods for such architectures suffer from inherent limitations due to coupled parameter constraints and restricted solution spaces caused by joint displacement and structural parameter dependencies. The presented methodology introduces three fundamental advancements: (1) a novel parameter assignment strategy enabling independent joint/link parameter definition across different kinematic chains, (2) systematic transformation of constrained optimization into an unconstrained one, and (3) significant expansion of error parameter solution space through virtual chain modeling. Comparative experiment on the physical prototype demonstrate improvements in both orientation and position accuracy compared to existing methods.

Micro-scale robots introduce great prospective into many different medical applications such as targeted drug delivery, minimally invasive surgery and localized bio-metric diagnostics. This research presents a method for object detection and tracking system of a chain-like magnetic microsphere robots using ultrasound imaging in an in-vitro environment. The method estimates the position of the microrobot in real-time using deep learning techniques. The experiments showed that a spherical microrobot with about 500 m in diameter can be detected and tracked in real-time with a high accuracy in dynamic environments. The results exhibit a high detection and tracking accuracy for one, two and three sphere microrobots with the highest accuracy in detection and tracking around 95 % and 93% respectively.

Wireless magnetic microrobots can perform complex tasks for small-scale minimally invasive surgery (MIS) that requires high precision and dexterity. The choice of the configuration of the electromagnetic actuation (EMA) system is a key issue for reliable medical applications. This paper addresses the study of a robotic EMA platform firstly devoted to ophthalmic MIS, aiming at improving the manipulability and dexterity of the procedure. To this end, a robotic EMA system comprising four static and four mobile electromagnets is investigated. Evaluation of the magnetic force and torque, the manipulability and the dexterity indexes of EMA platforms are studied. The results demonstrate that a robotic EMA platform increases the versatility of the EMA system, and becomes resourceful to perform various tasks.

This paper presents a novel permanent magnets based actuator capable of injecting and 2D wireless control the motion of an untethered microrobot. The actuator is obtained with a simple, but an effective arrangement of four permanent magnets. Its novelty is that it creates local maxima of the magnetic field magnitude in a planar workspace. This results in a convergence point for magnetic microrobots that are in its influence zone. Trapping microrobots in the local maxima makes their open-loop guidance possible, even in presence of reasonable perturbations. Actually, open-loop control is the only way to achieve some drug delivery when there are no sensors to provide us a feedback on the microrobot's positions. With the proposed actuator, the workspace is reduced, the movement is simplified and the actuator orientation is not needed anymore. Experimental results are provided in the paper to show the soundness of the proposed actuator design.

The use ofrobotic devices for drug delivery in sensitive area of the human body is an innovative and reliable solution. Most of them use magnetics fields, to steer micro-nano-robots into diseases locations. In this study, we use a magnetic actuator based on two permanent magnets as an end-effector of a robotic manipulator. The actuator offers the possibility to generate both pushing and pulling forces on the magnetic actuator axis in an open-loop control way. We describe in this paper the robotic drug delivery strategy that we implemented in a 6 degree of freedom robotic manipulator to push and to steer a magnetic microparticle from the round window to the apex of the human cochlea. Different experiments have been conducted in order to demonstrate the effectiveness and robustness of the navigation proposed strategy on a human phantom cochlea. The results demonstrate clearly that precise and reliable drug administration is rendered possible.

For actuating the magnetic microrobots, two types of magnetic actuation technologies have been used during the last past years. These magnetic technologies may be either electromagnetic coils or permanent magnets based systems. This second solution is not the most used by researchers, because of the difficulties to control the magnetic force. In this paper we propose a magnetic actuator prototype based on permanent magnets. In addition to the magnets, the actuator is also composed of a mechanical structure. This structure is used for positioning the permanent magnets, which allows to control the magnetic force generated by the actuator. We demonstrated in simulation and experimentally confirmed the ability of this actuator to generate both pushing and pulling forces.

This paper introduces a two-dimensional (2-D) autonomous navigation strategy of a 750-μm steel microrobot along a complex fluidic vascular network inside the bore of a clinical 3.0T magnetic resonance imaging (MRI) scanner. To ensure successful magnetic resonance navigation of a microrobot along consecutive channels, the design of autonomous navigation strategy is needed, taking into account the major MRI technological constraints and physiological perturbations, e.g., nonnegligible pulsatile flow, limitations on the magnetic gradient amplitude, MRI overheating, and susceptibility artifacts uncertainties. An optimal navigation planning framework based on Pareto optimality is proposed in order to deal with this multiple-objective problem. Based on these optimal conditions, a dedicated control architecture has been implemented in an interventional medical platform for real-time propulsion, control, and imaging experiments. The reported experiments suggest that the likelihood of controlling autonomously untethered 750-μm magnetic microrobots is rendered possible in a complex 2-D centimeter-sized vascular phantom. The magnetic microrobot traveled intricate paths at a mean velocity of about 4 mms-1with average tracking errors below 800 μm with limited magnetic gradients ±15 mTm-1, which is compatible with clinical MRI scanners. The experiments demonstrate that it is effectively possible to autonomously guide a magnetic microrobot using a conventional MRI scanner with only a software upgrade.

This paper presents an optimal control strategy for navigation of multiple magnetic microbeads for future drug targeting applications. To transport the drugs, we use therapeutic magnetic microbeads as navigable agents controlled by magnetic gradients. The main difficulty is to control independently each therapeutic agent along a trajectory with the same magnetic gradient fields. This study proposes an optimal control methodology to control a group of different therapeutic agents at desired states. Based on a dynamic model of group of magnetic microbeads, controllability and observability conditions are formulated and simulated. Based on the proposed theoretical analysis a linear quadratic with integral action control (LQI) has been chosen to be applied to the microbeads system. Finally, an experimental investigation is carried out in millimeter-sized fluidic artery vessels to demonstrate the controllability and stability of two magnetic microbeads under different velocity and trajectory constraints with a laminar viscous fluidic environment.

This paper describes the propulsion of the catalytic tubular microjet using Navier-Stokes equations. Especially, the thrust capability of the microjet is outstanding compared with the other microsystems, but remains only partially understood. Studies have identified the internal precursory mechanisms of the propulsion of the microjet: its inner wall catalyzes the dismutation of aqueous hydrogen peroxide, and an oxygen bubble is then formed and migrates towards its widest opening. This impulses the propulsion of the microjet towards the opposite direction. However, the precise propellant role of the liquid surrounding the jet remains misunderstood. The same goes for the inner wall of the vessel in which the jet navigates, especially in narrowed environment. This article discusses these aspects in a simplified theoretical framework. Calculations are performed by explicit computation of Navier-Stokes equations. The obtained theoretical outcome are in good agreement with experimental results in the literature.

This paper presents an optimal design strategy for magnetic targeting of therapeutic drugs. In this study, to maximize the effect of the treatment and minimize adverse effects on the patient, mathematical models have been developed to find the number and the size of the boluses with respect to the growth of a tumor. Using these models, control strategies are developed to establish a schedule that allows the physician to administer the medication while respecting borne by the patient doses. To transport the drugs, we use therapeutic magnetic boluses composed of magnetic particle aggregates as navigable agents controlled by magnetic gradients. Based on the optimal design of the bolus, an experimental investigation is carried out in millimeter-sized fluidic artery vessels to demonstrate the steerability of the magnetic bolus under different velocity, shear-stress and trajectory constraints with a laminar viscous fluidic environment.

This paper has presented a new vision-based force-sensing framework that allows to characterize the forces applied on a magnetic microrobot in an endovascular-like environment. Especially, unlike common approaches used with optical microscopy where orthographic projection model are used, we consider in this paper the weak-perspective model. The proposed vision-based force characterization allows to retrieve the three dimensional (3D) translational velocities and accelerations of a microrobot viewed from a digital microscope. Hence, thanks to the dynamic model the external forces are estimated on-line. The framework was applied and validated for a magnetic microrobot navigating in a viscous flow. Experimental results in two different environments illustrate the efficiency of the proposed method.

This paper reports a control strategy of a micro-gripper based on two AFM tips for manipulation at micro/nano scale. It is composed of dual micro/nano manipulators in order to handle and to maintain a microsample through the focus of a X-ray or laser beam for material characterization and analysis. The main idea is to control and to drive in a robust way the micro/nanomanipulators by focusing the beam on the center part of the handled micro-object. To this aim, the maximum intensity of the laser beam is measured in real-time by a four-quadrant photodiode sensor. As the sample under consideration here is a superparamagnetic microsphere of 8.2 μm (focusing laser spot less than few μm2), the laser tracking system is very sensitive to light intensity variations, mechanical vibrations, microhandling force perturbations and thermal relaxation of magnetic microsamples. First, we propose to compensate the laser beam variations by estimating the position of the laser beam using a particle filter (PF) algorithm. Then, a robust control strategy based on H∞controllers ensures a robust microhandling task under the focus of the laser beam whatever the external perturbations involved and parametric model uncertainties. The dual manipulators are controlled cooperatively by combining the different actuator dynamics to track a laser beam with nanometer precision. Finally, experimental results demonstrate the robustness of the microhandling task using the proposed robust control scheme.

Magnetic microrobotics was nowadays one of the most advanced technique to reach deep locations in human body for future biomedical applications. Different magnetic microrobot designs were proposed, such as bead pulling or microswimmers. In this paper, the use of chain-like of magnetic N-microspheres was investigated to enable new kind of motions and applications. An accurate theoretical model of chain-like magnetic microbeads navigating in viscous fluidic environments is described. Thus, the behavior of such microrobot was analyzed for different number of microspheres (ranging from N = 2 to 5). The efficiency of the proposed technique was demonstrated experimentally in a microfluidic vessel phantom to mimic atherosclerosis disease leading to plaque formation that fully occluded a vasculature.

Research activities on nanorobotics comprise an emerging interdisciplinary technology area raising new scientific challenges and promising revolutionary advancement in applications such as medicine, biology, and industrial manufacturing. Nanorobots can be defined as intelligent systems with overall dimensions at or below the micrometer range that are made of assemblies of nanoscale components while exploiting the physics at such a scale, or as larger platforms capable of robotic operations at the nanoscale. In an effort to disseminate the current advances in this specialized field of robotics, and to stimulate discussion on the future research directions while invigorating research interests towards the development and applications of nanorobotic systems, a special issue of this issue of IEEE TRANSACTIONS ON ROBOTICS (T-RO) has been dedicated to recent developments in nanorobotics. This Special Issue presents a total of 15 papers in the most active areas of research in nanorobotics. Six papers are dedicated to actuation presenting recent advances in the implementation, control, and modelling of actuation methods suited for such robots operating in low Reynolds hydrodynamic conditions and, more specifically, helical propulsion with the force being induced from a rotating magnetic field, resonant magnetic actuation, and self-propelled microjets and platinum catalytic mobile nanorobots. Four papers cover the very active field of research in nanorobotics is in biological and medical applications. The remainder look at industrial applications of micro/nanorobotic manipulation systems.

This study proposes molecular dynamics simulations used to derive guidelines for the design of the superparamagnetic nanocapsules (spherical-like or rod-like) dedicated to cross the brain-blood barrier (BBB) by magnetic forces. We focus our study on capillaries that have opened fenestrations when the integrity of the endothelial barrier is perturbed by tumors. We identified three different categories of governing parameters: geometrical (radius and length of nanocapsules), biophysical (ligand-to-receptor surface density ratio, nonspecific interaction parameters) and biological (ligand/receptor binding affinity). The main novelty of our study is to carry out computational simulations to determine design criteria-the size, charge, and shape of various magnetic nanocapsules (spherical and rod-shaped nanocapsules)-that optimize their penetration into the BBB. Finally, the simulation results show that the superparamagnetic nanorobotic capsules were able to cross the endothelial barrier by using magnetic forces compatible with medical constraints.

This paper presents a study of the control problem of a laser beam illuminating and focusing a microobject subjected to dynamic disturbances using light intensity for feedback only. The main idea is to guide and track the beam with a hybrid micro/nanomanipulator which is driven by a control signal generated by processing the beam intensity sensed by a four-quadrant photodiode. Since the pointing location of the beam depends on real-time control issues related to temperature variation, vibrations, output intensity control, and collimation of the light output, the 2D beam location to the photodiode sensor measurement output is estimated in realtime. We use the Kalman filter (KF) algorithm for estimating the state of the linear system necessary for implementing the proposed track-following control approach. To do so a robust master/slave control strategy for micro/nano dual-stage manipulators is presented based on sensitivity function decoupling design methodology. The decoupled feedback controller is synthesized and implemented in a 6 dof micro/nanomanipulator capable of nanometer resolution through several hundreds micrometer range. A case study relevant to tracking a laser-beam for imaging purposes is presented.

This paper discusses the control design of a magnetically guided microrobotic system in blood vessels to perform minimally invasive medical procedures. Such microrobots consist of a polymer-bonded aggregate of nanosized ferromagnetic particles and a possible payload that can be propelled by the gradient coils of a magnetic device. A fine modeling is developed and used to define an optimal trajectory which minimizes the control efforts. We then synthesize an adaptive backstepping law that ensures a Lyapunov stable and fine tracking, despite modeling errors, and estimates some key uncertain parameters. As the controller synthesis uses the microrobot unmeasured velocity, the design of a high-gain observer is also addressed. Simulations and experiment illustrate the robustness to both noise measurement and some uncertain physiological parameters for a 250-μm radius microrobot that navigates in a fluidic environment.

Navigating in bodily fluids to perform targeted diagnosis and therapy has recently raised the problem of robust control of magnetic microrobots under real endovascular conditions. Various control approaches have been proposed in the literature but few of them have been experimentally validated. In this paper, we point out the problem of navigation controllability of magnetic microrobots in high viscous fluids and under pulsatile flow for endovascular applications. We consider the experimental navigation along a desired trajectory, in a simplified millimeter-sized arterial bifurcation, operating in fluids at the low-Reynolds-number regime where viscous drag significantly dominates over inertia. Different viscosity environments are tested under a systolic pulsatile flow compatible with heart beating. The control performances in terms tracking, robustness and stability are then experimentally demonstrated.

MRI based nano- and microrobotics show good potential for new targeted therapies tackling e.g. cancer. In this paper, a system developed for the propulsion and navigation of small ferromagnetic objects only using clinical MRI systems is evaluated in experiments. The experiments include propulsion of an untethered ferromagnetic object against a pulsatile flow in a pipe system, navigation of an untethered object filled with ferromagnetic nanoparticles around obstacles in a free environment, and the choosing of a branch in a closed flow-less channel system when propelling an untethered ferromagnetic object. The system is found to deal with the tasks efficiently.

This work proposes molecular dynamics simulations used to derive guidelines for the design of the superparamagnetic nanocapsules (spherical-like or tubular-like) dedicated to cross the brain-blood barrier by magnetic forces. We focus our study on capillaries that have opened fenestrations when the integrity of the endothelial barrier is perturbed by tumors. We identified three different categories of governing parameters: geometrical (radius and length of nanocapsules); biophysical (ligand-to-receptor surface density ratio; non-specific interaction parameter) and biological (ligandreceptor binding affinity). It was demonstrated from MD simulations that the optimized size was for CNTs with dimensions greater than for 20 to 200 nm. Finally, the simulation results show that the superparamagnetic nanorobotic capsules were able to cross the endothelial barrier by using magnetic forces compatible with medical constraints.

Microinjection is a method for the delivery of exogenous materials into cells and is widely used in biomedical research areas such as transgenics and genomics. However, this direct injection is a time-consuming and laborious task, resulting in low throughput and poor reproducibility. Here, we describe a telerobotic shared control framework for microinjection, in which a micromanipulator is controlled by the shared motion commands of both the human operator and the autonomous controller. To determine the weightings between the operator and the controller, we proposed a quantitative evaluation method using a model of speed/accuracy trade-offs in human movement. The results showed that a 40%-60% weighting on the human operator (or the controller) produced the best performance for both speed and accuracy of guiding and targeting task in microinjection suggesting that some level of both automation and human involvement is important for microinjection tasks.

-A microrobot consisting of a polymer binded aggregate of ferromagnetic particles is controlled using a Magnetic Resonance Imaging (MRI) device in order to achieve targeted therapy. The primary contribution of this paper is the design of an adaptive backstepping controller coupled with a high gain observer based on a nonlinear model of a microrobot in a blood vessel. This work is motivated by the difficulty in accurately determining many biological parameters, which can result in parametric uncertainties to which model-based approaches are highly sensitive. We show that the most sensitive parameter, magnetization of the microrobot, can be measured using a Micro-Electro-Mechanical Systems (MEMS) force sensor, while the second one, the dielectric constant of blood, can be estimated on line. The efficacy of this approach is illustrated by simulation results.

Microinjection is the highly efficient delivery method of exogenous materials into cells, and it has been widely used in biomedical research areas such as transgenics and genomics. However, this direct injection task is time consuming and laborious, resulting in low throughput and poor reproducibility. This paper describes a telerobotic shared control (TSC) framework for the microinjection with high manipulation efficiencies, in which a micromanipulator is controlled by the shared motion commands of both the human operator (direct manipulation) and the autonomous controller. To determine the optimal gains between the operator and the controller, we proposed a quantitative evaluation method using Fitts' and steering laws. The results showed that a 40%-60% weighting on the human operator produced better performance for both speed and accuracy of task completion, and suggested that some level of automation or human involvement is important for microinjection tasks.

The propulsion of nano-ferromagnetic objects by means of MRI gradients is a promising approach to enable new forms of therapy. In this work, necessary techniques are presented to make this approach work. This includes path planning algorithms working on MRI data, ferromagnetic artifact imaging and a tracking algorithm which delivers position feedback for the microdevice and a propulsion sequence to enable interleaved magnetic propulsion and imaging. Using a dedicated software environment integrating path-planning methods and real-time tracking, a clinical MRI system is adapted to provide this new functionality for potential controlled interventional targeted therapeutic applications. Through MRI-based sensing analysis, this paper aims to propose a framework to plan a robust pathway to enhance the navigation ability to reach deep locations in human body. The proposed approaches are validated with different experiments.

This paper presents a complete computer-based biological training system to simulate intracytoplasmic sperm injection (ICSI) procedures in a virtual environment (VE). Using the proposed system, the technician can practice and improve his control by developing a gesture similar to that performed in reality. The human-machine user's interface also provides an efficient haptic-based guidance tool to minimize the risk of damaging membranes during the injection. The key challenge of deformable simulation is to satisfy the conflicting requirements of real-time interactivity and physical realism. The compromise between the realism of bio-mechanical models used, the accuracy and stability of computational algorithms for real-time haptic rendering are fullfilled with the use of a mechanical modeling based on a hyperelastic model (St-Venant-Kirchhoff) and the writing of a specific dynamic finite element code. Simulated responses are compared to experimental data to show the effectiveness of the proposed physically-based model.

In the current times, microelectromechanical systems and nanoelectromechanical systems form a major interdisciplinary area of research involving science, engineering, and technology. A lot of work has been reported in the area of modeling and control of these devices, with the aim of better understanding their behavior and improving their performance. This paper presents a review of the emerging advances in the modeling and control of these micro- and nanoscale devices and converges on the exciting research in on-chip control , with a mechatronics and controls perspective and concludes by projecting future trends.

A novel rotary nanomotor is described using two axially aligned, opposing chirality nanotube shuttles. Based on inter-shell screw-like motion of nanotubes, rotary motion is generated by electrostatically pulling the two cores together. Simulations using molecular dynamics show the generation of rotation from armchair nanotube pairs and their actuation properties. The simulation results, together with recently reported progress in realizing batch-fabricated ultra-high density nanotube shuttles, point towards the use of these motors as building blocks in nanoelectromechanical systems (NEMS) and nanorobotic systems for sensing, actuation, and computation applications.

This paper reports modeling and control of a microsized polymer aggregate of magnetic particles inside an artery, using a MRI device for supplying propulsion in order to achieve targeted chemotherapy. Non-Newtonian behavior of blood is considered, as well as wall effects and interactions, resulting in a highly nonlinear model. A backstepping approach is synthesized to ensure Lyapunov stability along a pre-planned trajectory inherited from the model, with robustness concerns.

This paper presents real-time MRI-based control of a ferromagnetic microcapsule for endovascular navigation. The concept was studied for future development of microdevices designed to perform minimally invasive interventions in remote sites accessible through the human cardiovascular system. A system software architecture is presented illustrating the different software modules to allow navigation of a microdevice in blood vessels, namely: (i) vessel path planner, (ii) magnetic gradient steering, (iii) tracking and (iv) closed-loop navigation control. First, the position recognition of the microrobot into the blood vessel is extracted using Frangi vesselness filtering from the pre-operation images. Then, a set of minimal trajectory is predefined, using FMM, to guide the microrobot from the injection point to the tumor area through the anarchic vessel network. Based on the pre-computed path, a GPC is proposed for robust time-multiplexed navigation along a 2D path in presence of pulsative flow. The simulation results suggest the validation of the proposed image processing and control algorithms. A series of disturbances introduced in the presence and absence of closed-loop control affirms the robustness and effectiveness of this predictive control system.

Comprehensive and training simulators that provide realistic visual and haptic feedback during cell indentation tasks are currently investigated. Complex cell geometry inherent to biological cells and intricate mechanical properties drive the need for precise mechanical and numerical modeling to assure accurate cell deformation and force calculations. Advances in alternative finite element formulation, such as mass-tensor approach, have reached the state where they are applicable to model soft cell deformation in real time. The geometrical characteristics and the mechanical properties for different cells are determined with AFM indentation. A real-time, haptics-enabled simulator for cell centered indentation has been developed which utilizes the atomic force microscopy data (mechanical and geometrical properties of embryonic stem cells (mESC)) to accurately replicate the indentation task and predict the cell deformation during indentation in real-time. This tool can be used as a mechanical marker to characterize the biological state of the cell. The operator is able to feel in real-time the change in the stiffness during cell deformation between fixed and live cells. A comparison study with finite element simulations using a commercial software and the experimental data demonstrate the effectiveness of the proposed physically-based model.

Piezoelectric-stack actuated platforms are utilized in many nanopositioning applications. Their performance is limited by their low-frequency resonance due to the mechanical construction as well as piezoelectric nonlinear effects. We propose a hybrid control scheme comprising a loop-shaping H∞controller and an inversion-based feedforward control scheme, capable of delivering accurate nanopositioning performance at relatively high speeds, upto 40 Hz. It is shown that the implemented control strategy is robust in the presence of uncertainty in resonance frequency due to loading. It is also shown that by employing charge actuation on the fast axis and integral tracking control on the slow axis, accurate raster scans can be obtained. Experimental results that show resonance damping, integral tracking action as well as the robustness of the implemented control scheme to resonance frequency uncertainty are presented. Finally, raster scans recorded at 10 Hz, 20 Hz and 40 Hz are presented to show the achievable positioning performance.

In current AFM-based nanomanipulation systems, the commercial position closed-loop controller for piezoelectric nanopositioning stages are implemented with success in a wide range of industrial applications. Even if these controllers operate with satisfactory nominal tracking performance, considerable attention has been focused on appropriate control strategies to compensate hysteresis, nonlinearities, drift and creep for high bandwidths and large scanning regimes. As these closed-loop controllers are very cost-effective, a special interest in robust plug-in compensators seems to be a solution. We proposed in this paper a robust plug-in compensator using the H-infinity loop-shaping techniques which can be plugged into the existing controller without affecting the already satisfactory nominal tracking performance of the existing closed-loop system. Dynamic modeling, identification and robust control of a 3 d.o.f. piezoelectric nanorobotic positioner are presented in this paper in order to improve the nanorobot performance under plant parameter variations and in the presence of external disturbances. Simulation and experimental results are given to validate the proposed plug-in robust compensator in the case of a nanorobotic manipulation task.

This paper reports the use of a MRI device to pull a magnetic microrobot inside a vessel and control its trajectory. The bead subjected to magnetic and hydrodynamic forces is first modeled as a nonlinear control system. Then, a backstepping approach is discussed in order to synthesize a feedback law ensuring the stability along the controlled trajectory. We show that this control law, combined with a high gain observer, provides good tracking performances and robustness to measurement noise as well as to some matched uncertainties.

In order to understand and characterize the mechanical property and response of the mouse embryonic stem cells (mESC), we used an atomic force microscope (AFM) combined with a PHANToM haptic feedback device. Atomic force microscopy has rapidly become a valuable tool for quantifying the biophysical properties of single cells or a collection of cells through force measurements. We report herein the mechanical characterization of single mESC using indentation-relaxation measurements with micro-sphere AFM probes for fixed and live undifferentiated mESC. During cell indentation for both live and fixed undifferentiated cells, we provided force feedback to the user in real-time through the PHANToM haptic feedback device as the AFM tip was deforming the cell. The force was amplified for the human operator to perceive the change in force during cell indentation by the AFM cantilever. This information can be used as a mechanical marker to characterize state of the cell (live and fixed). As the interpretation of atomic force microscopy-based indentation tests is highly dependent on the use of an appropriate theoretical model of the testing configuration, various contact models are presented to predict the mechanical behavior of an individual mouse embryonic stem cells (mESC) in different states. A comparison study with finite element simulations (FEM) of spherical tip indentation demonstrates the effectiveness of our computational model to predict the mESC deformation during indentation and relaxation nanomanipulation tasks.

In the context of virtualized-reality-based telemicromanipulation, this paper presents a visual calibration technique for an optical microscope coupled to a charge-coupled device (CCD) camera. The accuracy and flexibility of the proposed automatic virtual calibration method, based on parallel single-plane properties, are outlined. In contrast to standard approaches, a 3-D virtual calibration pattern is constructed using the micromanipulator tip with subpixel-order localization in the image frame. The proposed procedure leads to a linear system whose solution provides directly both the intrinsic and extrinsic parameters of the geometrical model. Computer simulations and real data have been used to test the proposed technique, and promising results have been obtained. Based on the proposed calibration techniques, a 3-D virtual microenvironment of the workspace is reconstructed through the real-time imaging of two perpendicular optical microscopes. Our method provides a flexible, easy-to-use technical alternative to the classical techniques used in micromanipulation systems.

Developments in the field of nano-biodevices coupling nanostructures and biological components are of great interest in medical nanorobotics. As the fundamentals of bio/non-bio interaction processes are still poorly understood in the design of these devices, design tools and multiscale dynamics modeling approaches are necessary at the fabrication pre-project stage. This paper proposes a new concept of optimized carbon nanotube based servomotor design for drug delivery and biomolecular transport applications. The design of an encapsulated DNA-multi walled carbon nanotube (DNA@MWNT) actuator is prototyped using a molecular dynamics simulator. Then, a multiscale dynamics model from the mechanics point of view is proposed through an atomistic-continuum approach. Based on the analysis of the simulation results, a servo nanoactuator using ionic current feedback is simulated and analyzed for application as a drug delivery carrier.

This paper presents a new architecture of control for microteleoperation system using a fault tolerant control (FTC) strategy to compensate for the degradation effects of microgipping system. The proposed strategy uses passivity approach for the bilateral controller and robust fault tolerant control (FTC) for the two-fingered microgripper system. First, the bilateral controller architecture uses the passivity approach for the teleoperation system in the presence of time delay and scaling factor variations. Second, the FTC controller is designed in such a way that the performance and robustness may be done separately which has the potential to overcome the conflict between performance and robustness in the traditional feedback framework. The slave controller architecture is controlled by the PI controller for a nominal model and the Hinfincontroller for faulty operation. The simulation and experimental results show clearly the effectiveness of the proposed approach.

To facilitate training of biological cell injection operations, we are developing an interactive virtual environment to simulate needle insertion into biological cells. A key challenge of deformable simulation is to satisfy the conflicting requirements of real-time interactivity and physical realism. This paper presents methodologies for dynamic modeling, visual/haptic display and model validation of cell injection. We first investigate the challenging issues in the modeling of the bio-mechanical properties of living cells. We propose a dynamic model to simulate cell deformation and puncture. The developed approach is based on the assumptions that the mechanical response of living cells is mainly determined by the cytoskeleton and that the cytoskeleton is organised as a tensegrity structure including microfilaments, microtubules and intermediate filaments. Equivalent microtubules struts are represented with a linear mass-tensor finite element model and equivalent microfilaments and intermediate filaments with viscoelastic Kelvin-Voigt elements. The virtual environment has been implemented with both graphic and haptic interfaces.

This paper describes the use of virtual fixtures and metaphors of assistance for robotic-assisted micromanipulation system in order to prevent the influence of microphysics on path planning and handling tasks. The system is based on a multimodal telemanipulation system using haptic/visual/sound interfaces for observation of microobjects under an optical microscope. Feasible haptically-generated paths based on potentials fields reaction forces and shock absorbers are described for efficient and safe pushing-based or adhesion-based micromanipulation. Then, metaphors with human sensory substitution are proposed in order to improve the perception of data or events. Finally, an experimental investigation carried out by nine trainees proves that the system guides efficiently and safely the operator's gesture. Moreover, user performance on a given task can increase as much as 52% in typical micromanipulation tasks.

Nanorobotic structure design and modeling require large-scale computer simulation tools and numerical algorithms in order to better understand, control and accelerate development of multiscale nanosystems. Research on modeling and simulation of physical, chemical and biological systems at the nanoscale will include techniques such as quantum mechanics, multi-particle simulation, molecular dynamics simulation, grain and continuum based models. In this paper, we present a novel approach that makes use of multi-scale and multi- physics modeling coupled to virtual reality for nanorobotic prototyping systems. First, a CAD system that integrated principles for multiscale approach in nanorobotics structure design is presented. Then, we focus in the different design levels, more specifically, the optimization of geometry structure carried out by quantum mechanics, molecular dynamics and continuum mechanics methodologies. As illustration of the proposed multiscale modeling concepts, we tested by simulation the dynamics characteristics of a nanorobotic parallel platform with one degree-of-freedom (DOF) composed of proteins-based passive kinematic chains and actuated by a viral protein-based nanoactuator. Multiscale simulations proved the effectiveness and accuracy of the proposed design and modeling approaches.

This paper presents a molecular mechanics study using a molecular dynamics software (NAMD) for characterization of molecular elastic joints for bio nanorobotic prototyping. Simple protein-like elastic joints elements for structural links have been carefully studied and simulated to understand the functional limits of each one of them: fibronectin, titin, deca-alanine, fibrillin, Rop and double-helical DNA molecules. We simulated the restoring forces involved under various external mechanical stress to predict the type of force spectra, reversibility, degrees of freedom and irreversible work that may be expected from single-molecule protein manipulation experiments. Their use as elementary molecular components for bio-nanorobotic structures are also simulated and the results discussed

This paper presents a new three-dimensional biomicromanipulation system for biological objects such as embryos, cells or oocytes. As the cell is very small, kept in the liquid, and observed through a microscope, the two-dimensional visual feedback makes difficult accurate manipulation in the 3-D world. To improve the manipulation work, we proposed an augmented human-machine interface. A 3-D visual information is provided to the operator through a 3-D reconstruction method using vision-based tracking deformations of the cell embryo. In order to stable injection tasks, the operator needs force feedback and haptic assistance during penetrating the cell envelop, the chorion. The proposed human-machine user's interface allows real-time realistic visual and haptic control strategies for constrained motion in image coordinates. Virtual haptic rendering allows to constrain the path of insertion and removal in the 3-D scene or to avoid cell destruction by controlling adequately position, velocity and force parameters

In this paper, a bilateral controller for a microteleoperation system is presented using passivity approaches. We showed that the application of wave variable formalism allows the passivity of the system in spite of the communication delays between the master and the slave and the varying scaling factors. Conditions of the passivity and of the transparency are given for the micro teleoperation system. Finally, experimental results are presented showing the stability-transparency performances of the resulting system with constant and variable time-delay

This paper presents a molecular mechanics study in new nanorobotic structures using molecular dynamics (MD) simulations coupled to virtual reality (VR) techniques. The operator can design and characterize through molecular dynamics simulation the behavior of bionanorobotic components and structures through 3-D visualization. The main novelty of the proposed simulations is based on the mechanical characterization of passive/active robotic devices based on double stranded DNA molecules. Their use as new DNA-based nanojoint and nanotweezer are simulated and results are discussed

This paper presents a new bio-micromanipulation system for biological object such as embryo, cell or oocyte. As the cell is very small, kept in the liquid, and observed through a microscope, the two-dimensional visual feedback makes difficult accurate manipulation in the 3-D world. To improve the manipulation work, we proposed an augmented human-machine interface. A 3-D visual information is provided to the operator through a 3-D reconstruction method using vision-based tracking deformations of the cell embryo. In order to stable injection tasks, the operator needs force feedback and haptic assistance during penetrating the cell envelop, the chorion. The proposed human-machine user’s interface allows real-time realistic visual and haptic control strategies for constrained motion in image coordinates. Virtual haptic rendering allows to constrain the path of insertion and removal in the 3-D scene or to avoid cell destruction by controlling adequately position, velocity and force parameters.

In the context of virtualized reality based telemicromanipulation, we present in this paper a visual calibration technique for optical microscope coupled with a CCD camera. In contrast to previous approaches, a virtual calibration pattern is constructed using the micromanipulator with a sub-pixel localization in the image. We also present a new camera calibration algorithm based on Parallel Single-Plane properties. The proposed procedure leads to a linear system from which the solution gives directly both intrinsic and extrinsic parameters of the geometrical model. Both computer simulation and real data have been used to test the proposed technique, and very good results have been obtained. Compared with classical techniques, our method provides an alternative technical solution, easy to use and flexible in the context of micromanipulation and virtual reality.

This paper presents a force-reflecting macro-micro teleoperator operating in a remote microenvironment with transmission time delays. In order to manipulate micro-objects, it is inevitable to consider the scaling effect problem between worlds with different physical characteristics, with minimal loss of physical information and robustness against variation of scaling gains. Accordingly, the controllers are designed based on the framework H/sub /spl infin// loop shaping procedure approach. This approach allows a convenient means to trade-off the robustness for a pre-specified time-delay margin, variation of force scaling factors and uncertainties in master and slave modeling. The validity of the proposed method is demonstrated by simulations.

Operators suffer much difficulty in manipulating micro/nano-sized objects without the assistance of human-machine interfaces due to scaling effects. We developed an immersive telemanipulation system using haptic/visual/sound interfaces for observation of micro-objects under an optical microscope. As the image of the microscope is two-dimensional, so it is hard to observe the workspace in the 3-D space. To improve the real-time observation and manipulation, we proposed real-time 3-D reconstruction of the microworld using image processing and virtualized reality techniques. Then, feasible haptically-generated paths based on potentials fields reaction forces are selected for efficient pushing-based manipulation without collisions. The proposed system guides the operator's gesture fully immerged in the virtual workspace.

Developments on micro/nano manipulation and Internet technologies allow potential impacts on networked-micro-automation of small industrial products. However, reliable and efficient tele-micromanipulation systems with haptic feedback over the Internet face strong problems due to the nonlinear nature of the microenvironment and time-varying delays in communication lines. Towards this end, this paper presents a robust bilateral controller design using H/sub /spl infin//-optimal control and /spl mu/-synthesis frameworks. This approach allows a convenient means to tradeoff the optimization of various performance criteria (micro scale force/position) and robustness for a prespecified time-delay margin and force scaling factors. The validity of the proposed method is demonstrated by simulations and experiments for a pick-and-place micromanipulation task.

This paper proposes a practical planning system for 2D assembly tasks at the microscale. To improve the real-time observation and manipulation, we proposed real-time 3-D reconstruction of the microworld using image processing and virtualized reality techniques. Then, a planner covers a whole range of problems in object assignment, obstacle detection and avoidance and path trajectory. We describe algorithms based on optimization theory and Voronoi graph construction. As automatic motion planners fail due to the difficulty of discovering critical configurations due to microdomain interactions, cooperation with operator skills is able to solve a motion planning query. The feasible haptically-generated paths based on potentials fields reaction forces are selected for efficient pushing-based manipulation without collisions.

This study aims to develop a force-reflecting macromicro teleoperator with different scaled worlds. A bilateral control system for scaled teleoperation provides the human operator with a feel of the task at the micro-scale. However, reliable and efficient tele-micromanipulation systems with haptic feedback over the Internet face to strong problems due to the nonlinear nature of microenvironment and time-varying delays in communication lines. A robust bilateral controller design framework using H/sub 2/-optimal control approach is proposed. A comparative study for assessing the robustness against time-varying delays is performed through two different designs, i.e., a /spl mu/-synthesis framework and a Pade approximation. The proposed approaches allow a convenient means to tradeoff the robustness for a pre-specified time-delay margin. The validity of the proposed method is demonstrated by simulations.

Remote control of microrobotic workstations dedicated to microassembly of hybrid MEMS is a challenging problem due to the lack of reliability and safety in microplanning procedures. It can be avoided by using virtual reality technology. Using the simulated environment in virtual reality, the operator can practice, explore and prevent the problems that occur during implementation. We proposed a concept of a physically behaved microrobotic workcell in virtual environment for microassembly teaching. In a first part, implementation of physical behaviors of virtual objects into VR for micro-task teaching is introduced. A virtual microworld is exactly reconstructed from the CAD-CAM databases of the real environment and simulates contact and elastic robotic interactions, virtual sensing of position and force, etc. Then, the virtual workcell is simulated and an example of micro-task teaching is given. The implementation includes view tracking using virtual force feedback, visual and audio rendering in virtual microenvironment.

The objective of this project, named MESIA (Multifunctional Micro-Endoscope Head System for Industrial Applications) is to develop an integrated multisensor system and to create intelligent sensor fusion for detection of micro-cracks. This paper is focused on the modeling of a 2-DOF pan-tilt platform actuated by Ni-Ti shape memory alloy (SMA) wires and antagonistic mechanical springs in order to control visually the CCD camera motion. A Preisach model is used and experimentally identified. The derived model is then exploited to design a position controller which compensates for the hysteretic nonlinearity. Finally, by controlling the catheter head orientation through a head motion tracker, in-pipe visual tracking has been experimentally verified from a remote site.

In this paper new intelligent control strategies are presented allowing a cooperative work between a human operator and a microassembly platform working in a partially structured microworld. Human integration is essential in the microworld where autonomous control alone would not be successful. The allocation of the control among human and robot occurs dynamically according to the state of the task execution. In the following, different task-level control issues (shared, traded, cooperative and priority) are discussed and tested on a micro device assembly workcell.

Remote control of microrobotic workstations dedicated to microassembly of hybrid MEMS consisting of several separate components are necessary. The operator controls the motion of the microrobots remotely on the motion level. In the future view of industrial applications, these approaches are not suitable. We proposed a concept of a desktop micro device factory for task-level remote control using the combination of vision servoing techniques and virtual reality (VR) environment. It is composed of two micromanipulators equipped with micro tools operating under a light microscope. First, we present the cooperation control strategy of the micro handling operation under vision-based position/force control integrating a sensor fusion framework approach. A guiding-system based on virtual micro-world exactly reconstructed from the CAD-CAM databases of the real environment being considered is presented for the imprecisely calibrated micro world. Finally, some experimental results of microassembly tasks performed on millimeter-sized components are provided.

This paper presents a new generation of compliant piezoelectric microconveyors for microobjects based on the cooperation of arrayed direct-drive standing wave ultrasonic actuators. A method using an equivalent electromechanical circuit is proposed for estimating and analysing the optimum driving force. On the basis of the proposed method, the friction drive optimization of the microrobot is performed through the implementation of an electromagnetic field-based preload controller. Preliminary experiments were also performed in order to demonstrate the proposed control method.

The paper presents a control strategy for a hyper redundant micromanipulator that has the particularity to have either a) binary joints: only a small finite number of position are allowed within min and max bounds and b) continuous joints: the joint can move continuously within its min and max bounds. The problem optimization is double: a) solve inverse kinematics for this kind of system and b) maximize the number of binary joints. We show that the hybrid nature of the manipulator make these problems nontrivial and we develop a parallel evolution strategy (ES) and genetic algorithm (GA) in response to this dual problem.