Workshop on "Robotic assembly of 3D MEMS".

Proceedings of a workshop proposed in IEEE IROS'2007.The increase of MEMS' functionalities often requires the integration of various technologies used for mechanical, optical and electronic subsystems in order to achieve a unique system. These different technologies have usually process incompatibilities and the whole microsystem can not be obtained monolithically and then requires microassembly steps. Microassembly of MEMS based on micrometric components is one of the most promising approaches to achieve high-performance MEMS. Moreover, microassembly also permits to develop suitable MEMS packaging as well as 3D components although microfabrication technologies are usually able to create 2D and "2.5D" components. The study of microassembly methods is consequently a high stake for MEMS technologies growth. Two approaches are currently developped for microassembly: self-assembly and robotic microassembly. In the first one, the assembly is highly parallel but the efficiency and the flexibility still stay low. The robotic approach has the potential to reach precise and reliable assembly with high flexibility. The proposed workshop focuses on this second approach and will take a bearing of the corresponding microrobotic issues. Beyond the microfabrication technologies, performing MEMS microassembly requires, micromanipulation strategies, microworld dynamics and attachment technologies. The design and the fabrication of the microrobot end-effectors as well as the assembled micro-parts require the use of microfabrication technologies. Moreover new micromanipulation strategies are necessary to handle and position micro-parts with sufficiently high accuracy during assembly. The dynamic behaviour of micrometric objects has also to be studied and controlled. Finally, after positioning the micro-part, attachment technologies are necessary

Freeform terahertz structures fabricated by multi-photon lithography and metal coating

Direct-write multi-photon laser lithography (MPL) combines highest resolution on the nanoscale with essentially unlimited 3D design freedom. Over the previous years, the groundbreaking potential of this technique has been demonstrated in various application fields, including micromechanics, material sciences, microfluidics, life sciences as well as photonics, where in-situ printed optical coupling elements offer new perspectives for package-level system integration. However, millimeter-wave (mmW) and terahertz (THz) devices could not yet leverage the unique strengths of MPL, even though the underlying devices and structures could also greatly benefit from 3D freeform microfabrication. One of the key challenges in this context is the fact that functional mmW and THz structures require materials with high electrical conductivity and low dielectric losses, which are not amenable to structuring by multi-photon polymerization. In this work, we introduce and experimentally demonstrate a novel approach that allows to leverage MPL for fabricating high-performance mmW and THz structures with hitherto unachieved functionalities. Our concept exploits in-situ printed polymer templates that are selectively coated through highly directive metal deposition techniques in combination with precisely aligned 3D-printed shadowing structures. The resulting metal-coated freeform structures offer high surface quality in combination with low dielectric losses and conductivities comparable to bulk material values, while lending themselves to fabrication on planar mmW/THz circuits. We experimentally show the viability of our concept by demonstrating a series of functional THz structures such as THz interconnects, probe tips, and suspended antennas. We believe that our approach offers disruptive potential in the field of mmW and THz technology and may unlock an entirely new realm of laser-based 3D manufacturing

Automated Micro-assembly tasks based on hybrid Force/position Control.

International audienceFull automated micro-assembly is an ongoing challenge for researchers. The use of force control constitutes a suitable approach to achieve automated micro-assembly. It takes into account microscale specificities like pull off forces, measurement resolution... The integration of force sensors in micro-assembly station is discussed. An experimental setup is proposed to achieve automated guiding tasks of 2mm x 50 μm x 50 μm microparts. It is based on two-sensing-finger microgripper of 2 mN force range. Interaction forces are modeled and used to establish suitable strategy for guiding according to stability conditions and response time. Control scheme which combines force and position control is proposed and its integration to dSPACE board for real time control is achieved. Automated guiding task is performed with dynamic rejection of perturbation within 35 ms and a ramp tracking with a contact force of 20 μN between the rail side and the micropart is obtained

Cyber-Physical Systems for Micro-/Nano-assembly Operations: a Survey

Abstract Purpose of Review Latest requirements of the global market force manufacturing systems to a change for a new production paradigm (Industry 4.0). Cyber-Physical Systems (CPS) appear as a solution to be deployed in different manufacturing fields, especially those with high added value and technological complexity, high product variants, and short time to market. In this sense, this paper aims at reviewing the introduction level of CPS technologies in micro/nano-manufacturing and how these technologies could cope with these challenging manufacturing requirements. Recent Findings The introduction of CPS is still in its infancy on many industrial applications, but it actually demonstrates its potential to support future manufacturing paradigm. However, only few research works in micro/nano-manufacturing considered CPS frameworks, since the concept barely appeared a decade ago. Summary Some contributions have revealed the potential of CPS technologies to improve manufacturing performance which may be scaled to the micro/nano-manufacturing. IoT-based frameworks with VR/AR technologies allow distributed and collaborative systems, or agent-based architectures with advance algorithm implementations that improve the flexibility and performance of micro-/nano-assembly operations. Future research of CPS in micro-/nano-assembly operations should be followed by more studies of its technical deployment showing its implications under other perspectives, i.e. sustainable, economic, and social point of views, to take full advance of all its features

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

Solution characterization and fabrication of hydrogel microstructures on an optical fiber

Sociomicrobiology has recently come to the forefront of bioanalytical research, primarily due to its physiological impact in the medical field. The interaction of bacterial cells in small, dense populations can reveal emergent properties of microbial communities, such as increased virulence and pathogenicity, as well as create a more accurate model for bacterial behavior in natural environments. Such systems are particularly relevant in mono- and polymicrobial communities, which exhibit social behaviors as well as the potential for symbiotic and/or adversarial interactions between species. The standard techniques for culturing bacteria lack the tools to provide adequate control over polymicrobial organization on a microscopic scale or to evaluate the spatiotemporal dynamics of bacterial interactions. Using our previously developed micro-3D printing platform, we can arrange cells in biocompatible, pico-liter sized containers, allowing us to overcome these prior spatial limitations. However, key questions still exist regarding the dynamics of interactions between distinct cellular populations. This dissertation focuses on the development of a modified micro-3D printing platform that enables us to fabricate protein-based structures around bacteria on the tip of a moveable substrate. Fabricating structures on moveable substrates such as a glass rod or optical fiber allows us to precisely tune where bacterial clusters are located in relation to varying stimuli and enables delivery of fabricated structures to remote environments such as chronic wounds. However, several challenges were faced in the development of this technique, such as optimization of fabrication solutions, successful layering of hydrogels of varying composition on glass rods, and creation of a custom-built fabrication setup for fabrication on optical fiber tips. Development of these techniques enables us to better appreciate the intricacies of sociomicrobial behavior and interactions, allowing for a better understanding of microbial responses leading to antibiotic resistance, and directing a better approach towards the treatment of various microbial infections.Chemistr