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In this paper a new gripper for microparts with dimensions of 200 to 3500 micrometers is presented that is especially designed for industrial suitability. This covers beside repeatability of position and force robustness of the mechanical structure, simple interfaces of the gripper's control structure and long service life. The minimization of the grippers size and weight is no superior objective because today's precision robots usually have sufficient payload and working space. To achieve this goal well tested technology from micro- an macro handling devices are combined. The new gripper is made up of a symmetrical guiding mechanism based on flexure hinges of aluminum and it is driven by a pneumatic actuator. In the first step the maximal gripping force can easily be limited by the working pressure of the pneumatic actuator. Standard open/ close commands provide a robust control interface. The technology of pneumatic actuation is well known and reliable. Since minimization of size is not the primary goal, a long service life can be achieved by limiting the mechanical stress in the flexure hinges. A skirt of aluminum protects the guiding device against destruction caused by collisions. The new gripper has been realized and has been used in a microassembly station where it proved its reliability and robustness in thousands of gripping cycles thus demonstrating its industrial suitability. An experimental evaluation was carried out in order to assess the properties of the gripper.
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Accurate handling of microparts is one of the major tasks for an automated microproduction. The development of centering electrostatic handling devices is described. Based on a planar design common microtechnical fabrication methods were used. Therefore the gripper electrodes can easily be miniaturized and the geometric form can be adapted to the shape of the objects to be handled. The optimization of the design of the gripper was done by using the Finite Element Method. This gave the possibility to improve the centering effect and the gripping forces without increasing the operating voltage. To enable the observation of the gripped parts with a camera, a transparent substrate was used (Pyrex-wafer). This facilitates the integration of the gripper into a sensor controlled microassembly station. Futhermore first successful tests of functional models are described.
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A large number of microgrippers has been developed in industry and academia. Although the importance of hybrid integration techniques and hence the demand for assembly tools grows continuously a large part of these developments has not yet been used in industrial production. The first grippers developed for microassembly were basically vacuum grippers and downscaled tweezers. Due to increasingly complex assembly tasks more and more functionality such as sensing or additional functions such as adhesive dispensing has been integrated into gripper systems over the last years. Most of these gripper systems are incompatible since there exists no standard interface to the assembly machine and no standard for the internal modules and interfaces. Thus these tools are not easily interchangeable between assembly machines and not easily adaptable to assembly tasks. In order to alleviate this situation a construction kit for modular microgrippers is being developed. It is composed of modules with well defined interfaces that can be combined to build task specific grippers. An abstract model of a microgripper is proposed as a tool to structure the development of the construction kit. The modular concept is illustrated with prototypes.
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This paper presents a micro gripper driven by a new piston type pneumatic micro actuator. The basic structure of the micro gripper and the actuator are fabricated by silicon dry etching in a single etch step. The device consists of a pyrex-silicon-pyrex sandwich structure which was mounted by anodic bonding. Alternatively a SU8 depth lithography process was used to realise the pneumatic driven micro gripper. The assembly of various micro parts including a recently presented tactile silicon 3D-micro probe is described.
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Production of complex Micro-Opto Electro-Mechanical Systems (MOEMS) often requires assembly of a system from individual components built by mutually incompatible processes. This fabrication step also constitutes the largest portion of the total cost (about 80%), and is one of the major roadblocks to successfully implementing a complex microsystem. Our previous experience with such systems shows, that gripping and manipulation of microparts significantly differs from the assembly of macroscopic devices. The main difference stems from the increased role of the surface electrostatic forces and the reduced influence of body forces such as gravity. This paper describes one possible use of the surface forces in the development of a novel optically transparent electrostatic microgripper. The principle of operation, design and simulation of the new device are described. Several models describing the gripping force are also presented. The out-of-plane and in-plane holding (frictional) forces are measured as a function of the applied voltage for two common materials - silicon and nickel. The fabrication sequence and the materials used are discussed.
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This paper describes a microgripper used for the micro-assembly of an artificial scaffold for tissue engineering. The porous sponge-like scaffold is a three dimensional construct built by tiny unit parts of biodegradable polymer. This application requires the assembly of several parts by applying a suitable level of force. In this framework, a monolithic shape memory alloy (SMA) microgripper was developed. It consists of two small fingers for grasping, an active part that changes its shape when heated and a parallel elastic structure used as a bias spring. The main aspect of the design is that all these elements are included within a single piece of material, but have different mechanical properties and serve as different functions. Using a new technology of Shape Memory Alloy laser annealing developed at EPFL, a local shape memory effect is introduced on the active part while leaving the remaining areas in a state where no shape memory effect occurs, i.e., in a cold-worked state. The parallel elastic structure is used to provide a pullback force on cooling as well as to guide the finger movement. An electrical path is integrated to heat the active part and drive the gripper by Joule effect. This paper focuses on the principle of the micro-gripper, its design, calculations and describes the fabrication process. Some first experimental results are also presented.
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A three-axial tactile micro probe for the investigation of the mechanical behavior of micro grippers and other micro assembly equipment has been developed using silicon micromachining technology. The sensor has been used to measure the restoring forces of flexural hinges in a micro gripper gear, to calibrate an integrated gripping force sensor, and to measure the generated forces of actuators used in micro grippers. The tactile micro probe is an advancement of a 3-D force sensor presented earlier.
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Implementing instruments in the form of wireless miniature robots designed to operate at the atomic scale requires a positioning system capable of atomic resolution over a relatively large surface area. Interferometers or similar instruments are not adequate for such an environment because of the high probability that another robot obstructs the path of the laser during position measurement. As such, we have developed an infrared system based on a position sensing detection technique mounted on an x-y stepping stage where the position of an infrared signal transmitted upward from a miniature wireless robot can be detected with a resolution of +/- 1.585 micrometers over a 0.5 meter diameter circular surface. Although a fleet of miniature robots distributed over a relatively large area can be supported simultaneously, the system is still far from reaching positioning accuracy down to the level of a single atom. This is why we are embedding the capability to detect surface features down to the size of a single atom using scanning tunneling microscopy (STM) techniques onto the miniature robots. The dynamic range of the scanning piezo-tube is one of many design issues that must be carefully planned. For instance, the scanning system must be capable of detecting each atom in the scan path in order to determine the distance by counting the number of atoms while the maximum scan range must reach the discrimination level of the infrared positioning system despite many artifacts such as non-linearity errors and hysteresis. The feasibility and the design of such system are described.
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When assembling MEMS devices or manipulating biological cells it is often beneficial to have information about the force that is being applied to these objects. This force information is difficult to measure at these scales and up to now has been implemented using laser-based optical force measurement techniques or piezoresistive devices. In this paper we demonstrate a method to reliably measure nanonewton scale forces applied to a micro scale cantilever beam using a computer vision approach. A template matching algorithm is used to estimate the beam deflection to sub-pixel resolution in order to determine the force applied to the beam. The template, in addition to containing information about the geometry of the beam, contains information about the elastic properties of the beam. Minimizing the error between this elastic template and the actual image by means of numerical optimization techniques, we are able to measure forces to within +/- 3 nN. In addition, we also discuss how this method can be generalized to measure forces in elastic configurations other than a simple cantilever beam. This opens up the possibility of using this method with specially designed micromanipulators to provide force as well as vision feedback for micromanipulation tasks.
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Microrobots are the result of increasing research activities at the border between microsystem technology and robotics. Today already, robots with dimensions of a few cubic- centimeters can be developed. Like conventional robots, microrobots represent a complex system that usually contains several different types of actuators and sensors. The measurement of gripping forces is the most important sensor application in micromanipulation besides visual servoing to protect the parts from too high surface pressures and thereby damage during the assembly process. Very small forces in the range of 200 (mu) N down to 0.1 (mu) N or even less have to be sensed. Thus, the aim of our current research activities is the development of a high-resolution integrated force microsensor for measuring gripping forces in a microhandling robot. On the one hand, the sensor should be a device for teleoperated manipulation tasks in a flexible microhandling station. On the other hand, typical microhandling operations should to a large extend be automated with the aid of computer-based signal processing of sensor information. The user should be provided with an interface for teleoperated manipulation and an interface for partially automated manipulation of microobjects. In this paper, a concept for the measurement of gripping forces in microrobotics using piezoresistive AFM (atomic force microscope) cantilevers is introduced. Further on, the concept of a microrobot-based SEM station and its applications are presented.
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At the EPFL, we have developed a force-feedback device and control architecture for high-end research and industrial applications. The Delta Haptic Device (DHD) consists of a 6 degrees-of-freedom (DOF) mecatronic device driven by a PC. Several experiments have been carried out in the fields of manipulation and simulation to assess the dramatic improvement haptic information brings to manipulation. This system is particularly well suited for scaled manipulation such as micro-, nano- and biomanipulation. Not only can it perform geometric and force scaling, but it can also include fairly complex physical models into the control loop to assist manipulation and enhance human understanding of the environment. To demonstrate this ability, we are currently interfacing our DHD with an atomic force microscope (AFM). In a first stage, we will be able to feel in real-time the topology of a given sample while visualizing it in 3D. The aim of the project is to make manipulation of carbon nanotubes possible by including physical models of such nanotubes behavior into the control loop, thus allowing humans to control complex structures. In this paper, we give a brief description of our device and present preliminary results of its interfacing with the AFM.
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Concerning the teleoperation between different scale worlds, it is important to take into account the scaling effect problem in terms of manipulator precision, human sensation, environment accessibility, dexterity, etc. To consider these different problems, this paper presents the development of a new macro-micro teleoperated micromanipulator, with two kinds of micromanipulation systems: a piezoelectric microgripper and an atomic force microscope (AFM) operating under an optical microscope. The natural force feedback sensation exerted on the piezoelectric microgripper is given through a teleoperated two-fingered planar hand mechanism. This system provides the human operator with natural force feedback sensation and augmented visual feedback while telemanipulating objects in the micro world. Firstly, the bilateral control system with active force feedback based on hybrid master-slave technologies is modeled. The results include the use of force feedback and power assist in order to demonstrate the feasibility and practicability of the micro-teleoperated system. Then, in order to improve the visual feedback issued form the optical microscope of the station, a virtual micro 3D environment is proposed. By combining 2D microscope images and augmented reality-based programming techniques, we reconstructed exactly the operational microworld. Finally, some experiments have been carried out in order to verify the validity of the proposed bilateral control scheme and to calibrate the developed virtual model incorporating visual and haptic feedback.
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Johann D. Burgert, Jan Malasek, Sylvain M. Martel, Colette Wiseman, Timothy Fofonoff, Robert Dyer, Ian Warwick Hunter, Nicholas Hatsopoulos, John Donoghue
The Telemetric Electrode Array System (TEAS) is a surgically implantable device for the study of neural activity in the brain. An 8x8 array of electrodes collects intra-cortical neural signals and connects them to an analog front end. The front end amplifies and digitizes these microvolt-level signals with 12 bits of resolution and at 31KHz per channel. Peak detection is used to extract the information carrying features of these signals, which are transmitted over a Bluetooth-based radio link at 725 Kbit/sec. The electrode array is made up of 1mm tall, 60-micron square electrodes spaced 500 microns tip-to-tip. A flex circuit connector provides mechanical isolation between the brain and the electronics, which are mounted to the cranium. Power consumption and management is a critical aspect of the design. The entire system must operate off a surgically implantable battery. With this power source, the system must provide the functionality of a wireless, 64-channel oscilloscope for several hours. The system also provides a low-power sleep mode during which the battery can be inductively charged. Power dissipation and biocompatibility issues also affect the design of the electronics for the probe. The electronics system must fit between the skull and the skin of the test subject. Thus, circuit miniaturization and microassembly techniques are essential to construct the probe's electronics.
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In the fields of micro positioning, micromanipulation and micro machining, the required motion precision is continuously increasing. The demand also increases for high dynamic performances (large bandwidth, high closed loop stiffness.). In many cases an inappropriate mechanical structure prevents to achieve these objectives. For example backlash or friction have to be reduced as much as possible. In this paper, we propose backlash-free and friction-free manipulators using flexure hinges and direct drive actuators. A three degrees of freedom (dof) parallel robot (X, Y, Z) that is a transposition in a flexible structure of the Delta robot kinematics is presented. We focus on the design and control of the robot. A simple dynamic model is proposed and compared with measurements. The system is characterized and we propose solutions to improve performances. These solutions are tested on a linear stage.
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In this paper a patented parallel structure will be presented in which conventional bearings are replaced by flexure hinges made of pseudo-elastic shape memory alloy. The robot has six degrees of freedom and was developed for micro assembly tasks. Laboratory tests made with the robot using conventional bearings have shown that the repeatability was only a couple of 1/100 mm instead of the theoretical resolution of the platform of < 1 micrometers . Especially the slip-stick effects of the bearings decreased the positional accuracy. Because flexure hinges gain their mobility only by a deformation of matter, no backlash, friction and slip-stick-effects exist in flexure hinges. For this reason the repeatability of robots can be increased by using flexure hinges. Joints with different degrees of freedom had to be replaced in the structure. This has been done by a combination of flexure hinges with one rotational degree of freedom. FEM simulations for different designs of the hinges have been made to calculate the possible maximal angular deflections. The assumed maximal deflection of 20 degree(s) of the hinges restricts the workspace of the robot to 28x28 mm with no additional rotation of the working platform. The deviations between the kinematic behavior of the compliant parallel mechanism and its rigid body model can be simulated with the FEM.
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The Monolithic PiezoActuator (MPA) described in this work proposes the amplification of the piezoelectric deformation by a lever mechanism designed in a bulk piezoceramic plate. The advantages of the monolithic approach are to make the structure compact and to avoid problems of assembling reducing consequently production costs. In addition, several DOF (Degree Of Freedom) MPA can be designed with this approach. The total displacement using the MPA can reach some microns for a few millimeters size device. A numerical model has been used to simulate the static and dynamic behavior of a 1 DOF MPA. Static and dynamic measurements show a maximum displacement of around 6 mm and bandwidths as high as 5 kHz. The second part of this work is devoted to the open-loop position control of the MPA. The piezoelectric actuation is generally known to have a static behavior with a good linearity. Actually, when such an actuator is controlled by the electrical voltage, the typical hysteresis between this voltage and the corresponding deformation of the actuator can reach 20% for a soft PZT. Experimental results show an hysteresis under 10% and weak non-linearity for the MPA compared to standard piezoactuators. In order to linearize the open-loop motions, an open-loop control device which control the quantity of free electrical charges on the micro-actuator has been developed. The implementation of the control method has also given very encouraging results for MPA prototypes used in the laboratory.
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This paper deals with a work in progress concerning the fabrication of an insect-like microrobot. Because of their large motions and their interesting density of energy, thermal actuation has been chosen to move this microrobot and an integrated structure has been held. Compliant thermal micro-actuators have been studied, fabricated and tested. The characterization and modeling of such kind of actuators have been done. Then, compliant microlegs for our microrobot were modelized and designed with two degrees of freedom for each leg. The design, operating cycle and process for the microfabrication of these microlegs will be given in this paper. The microlegs are constituted of two thermal bimorphs connected together with a microbeam. Several microlegs are fabricated on one silicone wafer and bonded on a printed board to allow their activation. The experimental results concerning the motions of these microlegs will be given. Based on the results of these first experiments, a second generation of microlegs were designed, fabricated and tested. Then the next step will be the microfabrication of the whole structure of the microrobot including their legs, in a monolithic way on one single silicon wafer.
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Based on small mobile robots the presented MINIMAN system provides a platform for micro-manipulation tasks in very different kinds of applications. Three exemplary applications demonstrate the capabilities of the system. Both the high precision assembly of an optical system consisting of three millimeter-sized parts and the positioning of single 20-μm-cells under the light microscope as well as the handling of tiny samples inside the scanning electron microscope are done by the same kind of robot. For the different tasks, the robot is equipped with appropriate tools such as micro-pipettes or grippers with force and tactile sensors. For the extension to a multi-robot system, it is necessary to further reduce the size of robots. For the above mentioned robot prototypes a slip-stick driving principle is employed. While this design proves to work very well for the described decimeter-sized robots, it is not suitable for further miniaturized robots because of their reduced inertia. Therefore, the developed centimeter-sized robot is driven by multilayered piezoactuators performing defined steps without a slipping phase. To reduce the number of connecting wires the microrobot has integrated circuits on board. They include high voltage drivers and a serial communication interface for a minimized number of wires.
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As part of a European Union ESPRIT funded research project a flexible microrobot system has been developed which can operate under an optical microscope as well as in the chamber of a scanning electron microscope. The system is highly flexible and configurable and uses a wide range of sensors in a closed-loop control strategy. This paper presents an overview of the vision system and its architecture for vision-controlled micro-manipulation. The range of different applications, e.g. assembly of hybrid microsystems, handling of biological cells and manipulation tasks inside an SEM, imposes great demands on the vision system. Fast and reliable object recognition algorithms have been developed and implemented to provide for two modes of operation: automated and semi-automated robot control. The vision system has a modular design, comprising modules for object recognition, tracking and depth estimation. Communication between the vision modules and the control system takes place via a shared memory system embedding an object database. This database holds information about the appearance and the location of all known objects. A depth estimation method based on a modified sheet-of-light triangulation method is also described. Furthermore, the novel approach of electron beam triangulation in the SEM is described.
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Piezo-actuators due to their relatively high resonant frequencies and small deflections are ideally suited as accurate displacement transducers. As such, they have been used to implement the legs of the miniature wireless NanoWalker robot where step sizes in the order of a few tenths of nanometers are required for final positioning within the range of an embedded instrument designed to operate at the atomic scale. The relatively high capacitance combined with the high-drive voltage requirement of the actuators, impose constraints on the miniaturization of the electronics. The amplitude modulation scheme requires one amplifier per quadrant electrode on the piezo-legs. Although power amplifiers are suited to drive large capacitive loads with large signal amplitudes without stability problems, the quiescent current of the amplifiers requires several DC/DC converters of significant size. During locomotion, the sudden current increase occurring when high slew rate signals are used during the charging/discharging cycle of the capacitive loads at each walking step, causes the power rail voltage to drop, yielding a reduction in the amplitude of the deflections of the piezo-legs. To minimize the number of DC/DC converters, the slew rate requirement of the drive signal is reduced by an increase of the angular acceleration of the leg created by an initial static friction force with the walking surface. It is then suggested that further miniaturization of the embedded electronics can be achieved by adjusting the kinematic behavior of the piezo-legs with an appropriate mechanical design and the right friction coefficient through careful materials selection.
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Amplitude modulated piezo-based locomotion requires one power amplifier for each quadrant electrode on the piezo-legs of miniature robots. Since each amplifier has a significant amount of quiescent current, several DC/DC converters must be embedded to source at least the total amount of quiescent current. In order to achieve a significant reduction in the overall size of the piezo-actuated robots, the number of DC/DC converters is reduced through frequency modulation. Using frequency modulation, the amplitudes of deflection or the step sizes are reduced by modulating the piezo-legs above the resonant frequency. Although the frequency modulated approach can result in much smaller robots than what can be achieved using the amplitude modulated technique, it has some drawbacks that the amplitude modulated approach does not have. First, the magnitudes of deflection of the piezo-legs using frequency modulation are typically more difficult to control. Secondly, for much smaller amplitudes of deflection, the onboard electronics must operate faster, yielding an increase in power consumption and an increase in temperature of the miniature robot, which in turn may affect sensitive embedded instruments. Furthermore, modulating the piezo-legs above the resonant frequency yields a reduction in efficiency, which translates into additional heat. When very small deflections are required, the risk of the temperature to rise beyond the Curie temperature of the piezo-material may also become an issue. All these factors must be considered carefully when frequency modulated piezo-based locomotion is used.
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The coordination of a fleet of miniature instrumented wireless robots operating within a half-meter diameter surface area requires a special infrastructure. The infrastructure described in this paper allows an excess of 100 of these robots to operate simultaneously and continuously at the atomic scale. Among many tasks, the infrastructure provides 4 Mb/s half-duplex infrared communication with all robots. It also provides an infrared positioning system based on a position sensing detection technique capable of positioning each robot within the whole workspace to +/- 1.585 mm. The positioning and angular information is also used by the infrastructure to control the displacements of all robots by communicating proper information and instructions to ensure that each robot reaches its assigned destination with minimum delay and without problems. While tracking the position and the status of each robot, a graphical user interface is also provided and updated, allowing user interactions. The infrastructure also includes a special power supply distribution scheme, a high precision walking and working surface, and electronics and software for the real-time automatic management of the nano-robotic platform.
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Sylvain M. Martel, Lorenzo Cervera Olague, Juan Bautista Coves Ferrando, Stefen Riebel, Torsten Koker, Jeremy Suurkivi, Timothy Fofonoff, Mark Sherwood, Robert Dyer, et al.
The NanoWalker is a miniature wireless instrumented robot designed for high-speed autonomous operations down to the atomic scale. As such, it requires very advanced electro-mechanical specifications and complex embedded sub-systems. The locomotion is based on three piezo-ceramic legs that are modulated at high frequencies to achieve several thousand steps per second with computer-controlled step sizes ranging from a few tenths of nanometers to a few micrometers. Each robot has an onboard 48 MIPS computer based on a digital signal processor (DSP) and 4 Mb/s half-duplex infrared communication system. A special instrument interface has been embedded in order to allow positioning capability at the atomic scale and sub-atomic operations within a 200 nanometer surface area using a scanning tunneling microscope (STM) tip. The design allows 200,000 STM-based measurements per second. In this paper, we describe the many sub-systems and the approaches used to successfully integrate them onto such a miniature robot.
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Bringing instruments capable of atomic scale operations in the form of miniature wireless robots yields very high-density powered electronics. As the robots are further miniaturized, the surface area available for heat dissipation becomes inadequate to maintain continuous operation of the onboard electronics. Typical approaches such as increasing the surface area by mounting a heat sink is not an option since it would increase substantially the overall size of the robot. The overall size has to be minimized to allow a larger fleet of miniature robots to operate simultaneously in the same area. A larger fleet translates to higher throughput for mass-scale atomic-level operations. To solve this issue, we have implemented a special skin in contact with the high-powered flexible electronic circuit surrounding the robot's body. The skin effectively dissipate heat by evaporating distilled water stored in a few layers of flexible patterned wiping fabric designed for maximum water absorption and encapsulated between an inner thin layer of thermally conductive elastometer and an outer thin layer of an heat conducting metal sheet. Without the skin, past experiments have shown that each robot would operate for approximately 10 seconds before shutting down. With a 1-mm thick skin on a 32-mm diameter size robot, experimental results have shown that each robot could operate up to approximately 5 minutes between refills. A thicker water absorption layer is not a valid option since it would increase the overall size of the robot. A refill methodology suitable for this environment is also described.
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With the trend of miniaturization of mechatronics products, the demands on microassembly increase substantially. Due to the scaling effect, handling and planning in microassembly is considerably different from those in conventional assembly. One important issue is to study how the environmental parameters will shape the scaling effect and consequently the handling of micro parts. A controlled environment will enable a better understanding of the handling tasks in microassembly and consequently provide a necessary tool for the development of model-based microassembly methods. Moreover, environmental parameters can affect the performance of microassembly system. This paper will present our progress of developing a microassembly station with controlled environment. The microassembly station includes a microassembly platform that is able to mount various tools such as microscopes, mobile stages, micro grippers, etc. The microassembly platform is installed in a controlled environment where temperature and humidity can be controlled, and mechanical vibration is damped. Such a microassembly station facilitates researching microassembly methods and techniques under different environmental conditions. Early study of the effects of environmental parameters to microassembly system and pick-and-place operation is reported as well.
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This paper describes a dynamical strategy for releasing objects picked-up by means of adhesion forces. Indeed, if sticking effects are used in order to capture an object by adequately choosing high surface energy constitutive material for the end-effector, these same effects handicap considerably the release. We propose to take advantage of the inertial effects of the end-effector and the manipulated object to overbalance adhesion forces and to achieve the release. For this purpose, accelerations as high as 105m/s2 are needed. Successful manipulation of a 40micrometers radius glass sphere is presented.
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This paper proposes a practical micro-object operation based on the dynamic analysis considering the adhesive effect under a scanning electron microscope (SEM). Recently, techniques of arranging micrometer-sized objects with high repeatability under a scanning electron microscope (SEM) are required to construct highly functional micro-devices. Since adhesion is dominant compared to gravity in the micro world, manipulation techniques using a needle-shaped tool by adhesive force are often adopted in basic researches where micro-objects are studied. These techniques, however, have not yet achieved the desired repeatability because many of these have been used just for the empirical reasons. Some even need the process of trial-and-error. Therefore, we analyze micro-object operation theoretically by introducing new physical factors, such as adhesive force and rolling-resistance, into the dynamic system consisting of a sphere, a needle-shaped tool, and a substrate. Through this analysis, we reveal that it is possible to fracture the contact interfaces selectively by controlling tool-loading angle reasonably. Based on the acquired knowledge, we also proposed the practical method of the pick and place operation of a micro-sphere under an SEM.
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Advanced Modular Micro-Production System (AMMS) is the title of a new concept which creates a suitable size ratio between microcomponents and the production environment. The concept is also ideal for the integration and interconnection of processes which have yet to be separated. The AMMS concept can be redesigned or extended in an easy and flexible manner. By using a modular construction, small dimensions and a decentrally-organized control architecture, high- precision and sensitive handling procedures could be automated with acceptable investment and operating costs.
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The microsystems field has seen only few standardization efforts so far. Si-based microtechnology profits from standardization in semiconductor technology mainly undertaken by SEMI. There is virtually no standardization neither for equipment nor for components in the Non-Si microtechnology. The main reason for this situation is the large variety of microcomponent shapes, sizes, materials, as well as manufacturing and assembly processes. While electronic assembly equipment is applicable for assembly as long as the microcomponents are chip-like such as pressure sensors, gas sensor arrays etc. the situation is different for hybrid microsystems, such as micro-optical and micro-fluidic systems. These systems are made up of microcomponents of different shapes and materials. This inherent variety has led to number of tailor made solutions, but to no real standardization of components or equipment so far. The German association of machine and plant manufacturers (VDMA) and the German standardization committee DIN NAFuO AA F3 have started standardization projects in the field of component and equipment standardization. These projects are supported by joint research projects.
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Production tools undergo a constant process of miniaturization. Technical, economical, as well as environmental reasons motivate this process. The research in the field of the Microfactory and Nanofactory addresses these issues. The question is how far and how fast will this miniaturization go? Does it make sense to have a factory so small that you can put it on your desk, next to you computer, and start to produce whatever you can imagine? Will Personal Factories (PF) ever exist? We first present different scenarios of the Personal Factory. One approach, which is generally favored by physicists, chemists and biologists, consists in the assembly of atoms or molecules, like LEGO-bricks, to build up complex devices (bottom up). We will not follow this approach in this paper. The second approach consists in the 3D microstructuring of the parts and their assembly (top down). We briefly present different structuring technologies that could apply in the PFs. We then briefly present micro-positioning systems developed at EPFL that could be used in assembly in PF.
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A fabrication technology is introduced for rapid structuring of glass components with microtools. The machining occurs in the vicinity of the tool tip in a NaOH solution without the necessity of mask design and lithography steps. The whole setup can be arranged on a table top unit outside the clean room. Especially the research field of MEMS or (mu) TAS could profit from this technology. The micro structures are drilled or milled into the glass substrates by spark assisted chemical etching (SACE) using micro tools that are dressed on the machine itself to correct for errors due to tool mounting (eccentricity and attitude). This tool processing is done with wire electrodischarge grinding (WEDG). A newly developed prototype is introduced that reduces the development time of micro devices that make use of glass components (Pyrex glass or quartz). Some research results on SACE are presented.
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At the Belgian institute IMEC techniques for the production of electrically conductive atomic force microscope (AFM) probes are developed. To facilitate handling of the fragile probes, holder chips are required. The assembly of such holder chips, which can be split up into the application of solder paste, the positioning of the holder chip and the soldering of the chip, is a crucial manufacturing step, that, until now, was performed manually for economic reasons. With the help of a modular micro assembly tool, developed by the Institute for Machine Tools and Industrial Management (iwb) of the Technische Universitaet Muenchen, an economical automated assembly of the holder chips was developed. Thanks to our integrated sensor technology, even the automated assembly onto the extremely fragile membranes of moulded AFM probes was possible. In particular, the dispensing process of the solder paste onto the membranes was improved by the integration of a non-contact sensor for the needle clearance.
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The paper deals with the development of a micropositioning station that can be used in manufacturing systems, microfactories, AFM or SNOM microscopes. The central element of the station is a standing waves ultrasonic linear motor. It is a jump-stick-slip driving mechanism that can make longitudinal and lateral shiftings, and rotations in the horizontal plane. Its main merits are its ability to perform microscale displacements and to support heavy pre-loads. An adequate drive-amplifier is developed, allowing the control of the system. Even, a phase sensitive vision method is developed to sense the position and the heading angle with an accuracy better than 0.2 pixel i.e. 12 micrometers with an observed field of about 4 x 3 cm2. A personnel computer controls the whole system.
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