Noise characterization in millimeter sized micromanipulation systems.

International audienceE cient and dexterous manipulation of very small (micrometer and millimeter sized) objects require the use of high precision micromanipulation systems. The accuracy of the positioning is nevertheless limited by the noise due to vibrations of the end e ectors making it di cult to achieve precise micrometer and nanometer displacements to grip small objects. The purpose of this paper is to analyze the sources of noise and to take it into account in dynamic models of micromanipulation systems. Environmental noise is studied considering the following sources of noise: ground motion and acoustic noises. Each source of noise is characterized in di erent environmental conditions and a separate description of their e ects is investigated on micromanipulation systems using millimeter sized cantilevers as end e ectors. Then, using the nite di erence method (FDM), a dynamic model taking into account studied noises is used. Ground motion is described as a disturbance transmitted by the clamping to the tip of the cantilever and acoustic noises as external uniform and orthogonal waves. For model validation, an experimental setup including cantilevers of di erent lengths is designed and a high resolution laser interferometer is used for vibration measurements. Results show that the model allows a physical interpretation about the sources of noise and vibrations in millimeter sized micromanipulation systems leading to new perspectives for high positioning accuracy in robotics micromanipulation through active noise control

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

Challenges in flexible microsystem manufacturing : fabrication, robotic assembly, control, and packaging.

Microsystems have been investigated with renewed interest for the last three decades because of the emerging development of microelectromechanical system (MEMS) technology and the advancement of nanotechnology. The applications of microrobots and distributed sensors have the potential to revolutionize micro and nano manufacturing and have other important health applications for drug delivery and minimal invasive surgery. A class of microrobots studied in this thesis, such as the Solid Articulated Four Axis Microrobot (sAFAM) are driven by MEMS actuators, transmissions, and end-effectors realized by 3-Dimensional MEMS assembly. Another class of microrobots studied here, like those competing in the annual IEEE Mobile Microrobot Challenge event (MMC) are untethered and driven by external fields, such as magnetic fields generated by a focused permanent magnet. A third class of microsystems studied in this thesis includes distributed MEMS pressure sensors for robotic skin applications that are manufactured in the cleanroom and packaged in our lab. In this thesis, we discuss typical challenges associated with the fabrication, robotic assembly and packaging of these microsystems. For sAFAM we discuss challenges arising from pick and place manipulation under microscopic closed-loop control, as well as bonding and attachment of silicon MEMS microparts. For MMC, we discuss challenges arising from cooperative manipulation of microparts that advance the capabilities of magnetic micro-agents. Custom microrobotic hardware configured and demonstrated during this research (such as the NeXus microassembly station) include micro-positioners, microscopes, and controllers driven via LabVIEW. Finally, we also discuss challenges arising in distributed sensor manufacturing. We describe sensor fabrication steps using clean-room techniques on Kapton flexible substrates, and present results of lamination, interconnection and testing of such sensors are presented

Automatic Microassembly of Tissue Engineering Scaffold

Ph.DDOCTOR OF PHILOSOPH

Workshop on "Control issues in the micro / nano - world".

International audienceDuring the last decade, the need of systems with micro/nanometers accuracy and fast dynamics has been growing rapidly. Such systems occur in applications including 1) micromanipulation of biological cells, 2) micrassembly of MEMS/MOEMS, 3) micro/nanosensors for environmental monitoring, 4) nanometer resolution imaging and metrology (AFM and SEM). The scale and requirement of such systems present a number of challenges to the control system design that will be addressed in this workshop. Working in the micro/nano-world involves displacements from nanometers to tens of microns. Because of this precision requirement, environmental conditions such as temperature, humidity, vibration, could generate noise and disturbance that are in the same range as the displacements of interest. The so-called smart materials, e.g., piezoceramics, magnetostrictive, shape memory, electroactive polymer, have been used for actuation or sensing in the micro/nano-world. They allow high resolution positioning as compared to hinges based systems. However, these materials exhibit hysteresis nonlinearity, and in the case of piezoelectric materials, drifts (called creep) in response to constant inputs In the case of oscillating micro/nano-structures (cantilever, tube), these nonlinearities and vibrations strongly decrease their performances. Many MEMS and NEMS applications involve gripping, feeding, or sorting, operations, where sensor feedback is necessary for their execution. Sensors that are readily available, e.g., interferometer, triangulation laser, and machine vision, are bulky and expensive. Sensors that are compact in size and convenient for packaging, e.g., strain gage, piezoceramic charge sensor, etc., have limited performance or robustness. To account for these difficulties, new control oriented techniques are emerging, such as[d the combination of two or more ‘packageable' sensors , the use of feedforward control technique which does not require sensors, and the use of robust controllers which account the sensor characteristics. The aim of this workshop is to provide a forum for specialists to present and overview the different approaches of control system design for the micro/nano-world and to initiate collaborations and joint projects

Design and realization of a microassembly workstation

With the miniaturization of products to the levels of micrometers and the recent developments in microsystem fabrication technologies, there is a great need for an assembly process for the formation of complex hybrid microsystems. Integration of microcomponents made up of different materials and manufactured using different micro fabrication techniques is still a primary challenge since some of the fundamental problems originating from the small size of parts to be manipulated, high precision necessity and specific problems of the microworld in that field are still not fully investigated. In this thesis, design and development of an open-architecture and reconfigurable microassembly workstation for efficient and reliable assembly of micromachined parts is presented. The workstation is designed to be used as a research tool for investigation of the problems in microassembly. The development of such a workstation includes the design of: (i) a manipulation system consisting of motion stages providing necessary travel range and precision for the realization of assembly tasks, (ii) a vision system to visualize the microworld and the determination of the position and orientation of micro components to be assembled, (iii) a robust control system and necessary fixtures for the end effectors that allow easy change of manipulation tools and make the system ready for the desired task. In addition tele-operated and semi-automated assembly concepts are implemented. The design is verified by implementing tasks in various ranges for micro-parts manipulation. The versatility of the workstation is demonstrated and high accuracy of positioning is shown

Design and implementation of a vision system for microassembly workstation

Rapid development of micro/nano technologies and the evolvement of biotechnology have led to the research of assembling micro components into complex microsystems and manipulation of cells, genes or similar biological components. In order to develop advanced inspection/handling systems and methods for manipulation and assembly of micro products and micro components, robust micromanipulation and microassembly strategies can be implemented on a high-speed, repetitive, reliable, reconfigurable, robust and open-architecture microassembly workstation. Due to high accuracy requirements and specific mechanical and physical laws which govern the microscale world, micromanipulation and microassembly tasks require robust control strategies based on real-time sensory feedback. Vision as a passive sensor can yield high resolutions of micro objects and micro scenes along with a stereoscopic optical microscope. Visual data contains useful information for micromanipulation and microassembly tasks, and can be processed using various image processing and computer vision algorithms. In this thesis, the initial work on the design and implementation of a vision system for microassembly workstation is introduced. Both software and hardware issues are considered. Emphasis is put on the implementation of computer vision algorithms and vision based control techniques which help to build strong basis for the vision part of the microassembly workstation. The main goal of designing such a vision system is to perform automated micromanipulation and microassembly tasks for a variety of applications. Experiments with some teleoperated and semiautomated tasks, which aim to manipulate micro particles manually or automatically by microgripper or probe as manipulation tools, show quite promising results

Recent advances in the study of Micro/Nano Robotics in France.

International audienceIn France, during the last decade, significant research activities have been performed in the field of micro and nano robotics. Generally speaking the microrobotic field deals with the design, the fabrication and the control of microrobots and microrobotic cells. These microrobots are intended to perform various tasks in the so-called Microworld. The scale effects from macroworld to microworld deeply affect robots in the sense that new hard constraints appear as well as new manufacturing facilities. Concerning the nanorobotics, in order to achieve high-efficiency and three-dimensional nanomanipulation and nanoassembly, parallel imaging/manipulation force microscopy and three-dimensional manipulation force microscope, as well as nanmanipulation in the scanning electron microscope, have been developed. Manipulation of nanocomponents, such as nanoparticles, nanowires and nanotubes, have been addressed to build two-dimensional nano patterns and three-dimensional nano structure

Hybrid optical and magnetic manipulation of microrobots

Microrobotic systems have the potential to provide precise manipulation on cellular level for diagnostics, drug delivery and surgical interventions. These systems vary from tethered to untethered microrobots with sizes below a micrometer to a few microns. However, their main disadvantage is that they do not have the same capabilities in terms of degrees-of-freedom, sensing and control as macroscale robotic systems. In particular, their lack of on-board sensing for pose or force feedback, their control methods and interface for automated or manual user control are limited as well as their geometry has few degrees-of-freedom making three-dimensional manipulation more challenging. This PhD project is on the development of a micromanipulation framework that can be used for single cell analysis using the Optical Tweezers as well as a combination of optical trapping and magnetic actuation for recon gurable microassembly. The focus is on untethered microrobots with sizes up to a few tens of microns that can be used in enclosed environments for ex vivo and in vitro medical applications. The work presented investigates the following aspects of microrobots for single cell analysis: i) The microfabrication procedure and design considerations that are taken into account in order to fabricate components for three-dimensional micromanipulation and microassembly, ii) vision-based methods to provide 6-degree-offreedom position and orientation feedback which is essential for closed-loop control, iii) manual and shared control manipulation methodologies that take into account the user input for multiple microrobot or three-dimensional microstructure manipulation and iv) a methodology for recon gurable microassembly combining the Optical Tweezers with magnetic actuation into a hybrid method of actuation for microassembly.Open Acces