This paper furnishes the theoretical basis to perform the calibration of one or more ultra-high-precision industrial robots operating in the same workspace. We propose a new calibration procedure that keeps in account the factors that lower the robot accuracy at nanometer scale. To validate this approach, we present the practical case of the calibration of a two industrial robots system. Finally, we propose nano-indentation as an alternative method to evaluate the final accuracy reached by the system after calibration.

While dealing with sub-micrometer precision robots, thermal expansion is the most significant source of inaccuracy. Thermal variations in the environment, in the robot parts and in the frame change the robot geometry, lowering the robot precision. In this article we propose a strategy to model and compensate such effects. The thermal behavior of a 3 DOF (Degree(s)-of-freedom) parallel robot has been studied using a high-precision measuring system. A model of the robot thermal behavior has been built and implemented in the controller. By using it, thermal deformations are compensated in real-time and an absolute accuracy of ±71 nm has been reached.

Carbon nanotubes (CNTs) are one of the most promising materials for nanoelectronic applications. Before bringing CNTs into large-scale production, a reliable nanorobotic system for automated handling and characterization as well as prototyping of CNT-based components is essential. This paper presents the NanoLab setup, a nanorobotic system that combines specially developed key components such as electrothermal microgrippers and mobile microrobots inside a scanning electron microscope. The working principle and fabrication of mobile microrobots and electrothermal microgripper as well as their interaction and integration is described. Furthermore, the NanoLab is used to explore novel key strategies such as automated locating of CNTs for pick-and-place handling and methods for electrical characterization of CNTs. The results have been achieved within the framework of a European research project where the scientific knowledge will be transfered into an industrial system that will be commercially available for potential customers.

Pelvic motions are of great importance while walking, and have thus to be taken into account when developing and controlling rehabilitation devices. This paper will first introduce a new reeducation device for paraplegic people: the WalkTrainer. This device is composed of a leg and pelvic orthosis, an active bodyweight support and closed loop muscle stimulation. Second, the six degrees of freedom (DOF) of the pelvis will be measured by using the WalkTrainer on a population of twenty healthy subjects. Each DOF was successfully measured and can be analyzed as a function of time or gait cycle. Third several models that predict the pelvic motion amplitude as a function of various parameters (speed, size, ...) will be proposed and analyzed. Fourth, pelvic trajectories will be programmed on the WalkTrainer and applied on healthy subjects by the mean of the pelvic orthosis. In that phase one of the previously proposed models will be implemented. A force reduction of 20% is measured on the pelvic orthosis when the pelvic motion amplitude prediction model is used. At last muscle identification and stimulation will be introduced in the future works chapter.

The "modulated friction inertial drive (MFID) principle" is presented as a locomotion solution for mm- size micro robots dealing with both size constraints and limitations in terms of power consumption. Based on one of the configurations of this locomotion principle a locomotion module (10 times 10 mm2) with two degrees of freedom (X, thetasz) has been developed. It consists of two horizontally vibrating masses actuated by electrostatic comb drives and fabricated by DRIE on a SOI wafer. The design as well as calculated and measured actuator displacements and resonance frequencies are presented. First locomotion experiments have shown a linear velocity of 0.207 mm/s for a driving voltage of 30 Vp2pand a power consumption of only 16.6 muW.

In this paper a 3 DOF in translation high-precision parallel manipulator having flexure hinges is considered for the purpose of studying its performances in terms of absolute positioning accuracy in presence of different sources of inaccuracy. Manufacturing errors, gravity and temperature gradients are the sources of inaccuracy analyzed by means of FEM simulation models. The obtained data is used to benchmark the different sources studied and to establish a theoretical limit for the positioning performances of the manipulator. The kinematic analysis is performed using simulation models.

This paper presents a monolithic shape memory alloy (SMA) microgripper, which was developed to assemble microscopic building blocks of width 60 /spl mu/m into tissue engineering scaffolds. It consists of two small fingers for grasping, an actuator which changes its shape upon heating by Joule effect and a parallel elastic structure to provide a pullback force on cooling as well as to guide the finger movement. All the elements are laser-cut from the same Ni-Ti-Cu sheet but have different mechanical properties and are used for different functions. Using local laser annealing, a local shape memory effect is introduced on the actuator while leaving other areas in a cold-worked state, i.e. no shape memory effect occurs. The material has nonlinear mechanics and the actuator undergoes large deflections. A numerical method is introduced to compute the nonlinear dynamics of the coupled system formed by the actuator and pullback spring. The predicted deflection and force are in good agreement with the measured ones, and this model can be used to optimize the design.

Describes an integrated approach to design and fabricate scaffold/cell constructs for tissue engineering. With this approach it becomes possible to produce scaffolds with controlled distribution of living cells and growth factors, a critical condition for successful grafting. Our idea consists of building a scaffold/cell construct by robotic micro-assembly of microscopic polymer building blocks. The paper introduces the rationale and concept of this interdisciplinary project and presents some realized steps. A 3D contact FEM simulation has been carried out to study the forces involved on the scaffold elements and micro-gripper during assembly. An error analysis has been performed to evaluate the accumulated error when building a scaffold/cell construct. A dedicated monolithic shape memory alloy micro-gripper has been realized and tested, which is able to handle parts in the range of 50-100 microns.

Illustrates with various practical examples an activity at the intersection of MEMS, system control, robotics and ultraprecision design. The resulting new application domains include microrobotics, microfactories and nanotechnologies.

This paper presents several approaches for piezoactuators in motion control over a large dynamic range (cm to nm). The devices include monolithic two-degree-of-freedom actuators with mechanical amplification, stick-slip actuators and 6-DOF designs of micro-positioners. Closed loop feedback is of course necessary for good performance. All the proposed solutions have been realized and experimental results are discussed, application examples in scanning probe microscopy and biology are shortly presented.

This paper deals with the mechanical design and control of a novel 4-DOF force-reflecting manual man-machine interface for virtual reality based minimally invasive surgery simulation for training purposes. The realized force feedback manipulator is based on a novel spherical remote-center-of-motion mechanical structure, and features compactness, high sustained output force capability, low friction, zero backlash, and a particularly large, singularity-free workspace. An implicit force control scheme is employed for virtual object impedance simulations. Active compensation of manipulator gravity and actuator friction allows one to simulate static and dynamic object attributes including weight, elasticity, and viscosity over a wide dynamic range of approximately 1:100. Finally, a novel 'supervisory control' concept is proposed which allows one to connect the haptic feedback system to the corresponding graphical simulation environment with highly differing bandwidth requirements.

Force reflecting manual man-machine interfaces can provide the user with useful kinesthetic information in teleoperation tasks and virtual reality applications. In this paper we discuss the design of a novel spherical remote-center-of-motion manipulator for force reflection in a laparoscopic surgery simulation environment. A description of the pantograph-linkage based parallel structure is presented together with a discussion of its direct and inverse geometric models, instantaneous kinematics and statics, and usable workspace.