A Review of Haptic Feedback Teleoperation Systems for Micromanipulation and Microassembly

International audienceThis paper presents a review of the major haptic feedback teleoperation systems for micromanipulation. During the last decade, the handling of micrometer-sized objects has become a critical issue. Fields of application from material science to electronics demonstrate an urgent need for intuitive and flexible manipulation systems able to deal with small-scale industrial projects and assembly tasks. Two main approaches have been considered: fully automated tasks and manual operation. The first one require fully pre determined tasks, while the later necessitates highly trained operators. To overcome these issues the use of haptic feedback teleoperation where the user manipulates the tool through a joystick whilst feeling a force feedback, appears to be a promising solution as it allows high intuitiveness and flexibility. Major advances have been achieved during this last decade, starting with systems that enable the operator to feel the substrate topology, to the current state-of-the-art where 3D haptic feedback is provided to aid manipulation tasks. This paper details the major achievements and the solutions that have been developed to propose 3D haptic feedback for tools that often lack 3D force measurements. The use of virtual reality to enhance the immersion is also addressed. The strategies developed provide haptic feedback teleoperation systems with a high degree of assistance and for a wide range of micromanipulation tools. Based on this expertise on haptic for micromanipulation and virtual reality assistance it is now possible to propose microassembly systems for objects as small as 1 to 10 micrometers. This is a mature field and will benefit small-scale industrial projects where precision and flexibility in microassembly are required

Optimization of the size of a magnetic microrobot for high throughput handling of micro-objects.

International audienceOne of the greatest challenges in microrobotic is to handle individually a large number of objects in a short time, for applications such as cell sorting and assembly of microcomponents. This ability to handle a large number of microobjects is directly related to the size of the microrobot. This paper proposes a theoretical study of the size of a magnetic microrobot maximizing its capacity of displacement. It demonstrates that there is an optimal size can be obtained, due to a trade-off between the inertial and the viscous effects. Analyticalexpressions of the optimal size and the related frequency of motion are derived from a simplified model to highlight the influence of the geometrical and the physical parameters of the magnetic manipulation system such as the viscosity of the liquid and the size of the workspace. A numerical simulation validates the analytical analysis and demonstrates a high displacement capacity of the microrobot (around 100 back and forth motions per second for a robot of around 20 µm in water)

An overview of multiple DoF magnetic actuated micro-robots.

International audienceThis paper reviews the state of the art of untethered, wirelessly actuated and controlled micro-robots. Research for such tools is being increasingly pursued to provide solutions for medical, biological and industrial applications. Indeed, due to their small size they o er both high velocity, and accessibility to tiny and clustered environments. These systems could be used for in vitro tasks on lab-on-chips in order to push and/or sort biological cells, or for in vivo tasks like minimally invasive surgery and could also be used in the micro-assembly of microcomponents. However, there are many constraints to actuating, manufacturing and controlling micro-robots, such as the impracticability of on-board sensors and actuators, common hysteresis phenomena and nonlinear behavior in the environment, and the high susceptibility to slight variations in the atmosphere like tiny dust or humidity. In this work, the major challenges that must be addressed are reviewed and some of the best performing multiple DoF micro-robots sized from tens to hundreds m are presented. The di erent magnetic micro-robot platforms are presented and compared. The actuation method as well as the control strategies are analyzed. The reviewed magnetic micro-robots highlight the ability of wireless actuation and show that high velocities can be reached. However, major issues on actuation and control must be overcome in order to perform complex micro-manipulation tasks

Variable gain haptic coupling for molecular simulation

Molecularinteractionstypicallyhaveahighdynamicrange(HDR), combining short-range stiff repulsive effects with long-range, soft attractive and repulsive terms. As a result, faithful haptic renderingofsuchmolecularinteractionsisbothimportantanddifficult,in particularinapplicationswherethepreciseperceptionofmolecular forces is necessary (e.g. in molecular docking simulations). Traditionally,teleoperationcouplingusingconstantgaincontrolschemes have limited applications since they are unable to transmit to users low attractive forces without truncating repulsive ones. Furthermore, constant scaling displacement induces either instability or time-consuming experiments (displacements are slow), which deteriorates the ease of manipulation. In this paper, we describe a variable gain haptic coupling method specifically designed to render high dynamic range (molecular) forces. The proposed method is evaluated by user tests on an experiment involving two water molecules. We observe that variable force amplification is widely appreciated, whereas variable displacement scaling is appropriated only for users familiar with haptic manipulation. A complex experiment on a HIV molecule is carried out using this variable gain system. Advantages and limitations of thisapproach arediscussed.

Haptic feedback in teleoperation in Micro-and Nano-Worlds.

International audienceRobotic systems have been developed to handle very small objects, but their use remains complex and necessitates long-duration training. Simulators, such as molecular simulators, can provide access to large amounts of raw data, but only highly trained users can interpret the results of such systems. Haptic feedback in teleoperation, which provides force-feedback to an operator, appears to be a promising solution for interaction with such systems, as it allows intuitiveness and flexibility. However several issues arise while implementing teleoperation schemes at the micro-nanoscale, owing to complex force-fields that must be transmitted to users, and scaling differences between the haptic device and the manipulated objects. Major advances in such technology have been made in recent years. This chapter reviews the main systems in this area and highlights how some fundamental issues in teleoperation for micro- and nano-scale applications have been addressed. The chapter considers three types of teleoperation, including: (1) direct (manipulation of real objects); (2) virtual (use of simulators); and (3) augmented (combining real robotic systems and simulators). Remaining issues that must be addressed for further advances in teleoperation for micro-nanoworlds are also discussed, including: (1) comprehension of phenomena that dictate very small object (< 500 micrometers) behavior; and (2) design of intuitive 3-D manipulation systems. Design guidelines to realize an intuitive haptic feedback teleoperation system at the micro-nanoscale level are proposed

Stability and Transparency Analysis of a Teleoperation Chain For Microscale Interaction.

International audienceMicroscale teleoperation with haptic feedback requires scaling gains in the order of 104 107. These high gains impose a trade-off between stability and transparency. Due to the conservative approach used in most designs, transparency is reduced since damping is added to the system to guarantee stability. Starting from the fact that series, negative feedback and parallel connection of passive systems is a passive system, a new approach is addressed in this work. We propose here a complete teleoperation chain designed from the ground up for full transparency and stability, including a novel self-sensing probe and a high fidelity force-feedback haptic interface. By guaranteeing the passivity of each device and assuming that the human operator and the environment are passive systems, a homothetic direct coupling can be used without jeopardizing the stability and provides best transparency. The system is experimentally demonstrated in the complex case of a probe interacting with a water droplet under human control, while accurately transcribing the interaction back to operator

Vision-based haptic feedback for remote micromanipulation in-SEM environment.

International audienceThis paper presents an intuitive environment for remote micromanipulation composed of both haptic feedback and virtual reconstruction of the scene. To enable non expert users to perform complex teleoperated micromanipulation tasks it is of utmost importance to provide them with information about the 3D relative positions of the objects and the tools. Haptic feedback is an intuitive way to transmit such information. Since position sensors are not available at this scale, visual feedback is used to derive information about the scene. In this work, three different techniques are implemented, evaluated and compared to derive the object positions from scanning electron microscope images. The modified correlation matching with generated template algorithm is accurate and provides reliable detection of objects. To track the tool, a marker based approach is chosen since fast detection is required for stable haptic feedback. Information derived from these algorithms is used to propose an intuitive remote manipulation system, that enables users situated in geographically distant sites to benefit from specific equipments such as SEMs. Stability of the haptic feedback is ensured by the minimization of the delays, the computational efficiency of vision algorithms and the proper tuning of the haptic coupling. Virtual guides are proposed to avoid any involuntary collisions between the tool and the objects. This approach is validated by a teleoperation involving melamine microspheres with a diameter of less than 2 m between Paris, France and Oldenburg, Germany

2D robotic control of a planar dielectrophoresis-based system.

International audienceNanosciences have recently proposed a lot of proofs of concept of innovative nanocomponents and especially nanosensors. Going from the current proofs of concept on this scale to reliable industrial systems requires the emergence of a new generation of manufacturing methods able to move, position and sort micro-nano-components. We propose to develop 'No Weight Robots-NWR' that use non-contact transmission of movement (e.g. dielectrophoresis, magnetophoresis) to manipulate micro-nano-objects which could enable simultaneous high throughput and high precision. This paper focuses on developing a 2D robotic control of the trajectory of a microobject manipulated by a dielectrophoresis system. A 2D dynamic model is used to establish an open loop control law by a numerical inversion. Exploiting this control law, a high speed trajectory tracking (10 Hz) and high precision positioning can be achieved. Several simulated and experimental results are shown to evaluate this control strategy and discuss its performance

Design and first experiments on MagPieR, the magnetic microrobot.

International audienceThis article deals with the design, the actuation and the control of magnetic microrobots. The interest in such microscale robots actuated by remote force fields is increasing since a large range of application fields could benefit from these small size manipulators. However major scientific challenges such as the optimization of the actuation platform, or the reduction of the adhesion between the robot and the substrate must still be overcome to perform complex micromanipulations. This article presents an example of a magnetic microrobot, MagPieR. Its design, fabrication, actuation and control are detailed. First experiments are presented, and the issues that must still be overcome are highlighted

Haptic molecular simulation based on force control

International audienceIn this paper, force control is proposed to connect a molecular simulator to a haptic device. Most of the works dealing with this kind of simulators use position control to manipulate the molecules, with major stability concerns. These two control modes are compared in terms of adequacy with the molecular simulator. Stability with respect to the scaling coefficients introduced to connect the macro and the nanoworlds is also considered. The theoretical results and the experiments carried out confirm that position control is sensitive to the gain tuning. Force control enables to get stable force feedback for varying gains, and is thus a promising coupling to perform manipulations on complex molecular systems