Download or read book Capillary Forces in Microassembly written by Pierre Lambert and published by Springer Science & Business Media. This book was released on 2007-08-29 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Capillary Forces in Microassembly discusses the use of capillary forces as a gripping principle in microscale assembly. Clearly written and well-organized, this text brings together physical concepts at the microscale with practical applications in micromanipulation. Throughout this work, the reader will find a review of the existing gripping principles, elements to model capillary forces as well as descriptions of the simulation and experimental test bench developed to study the design parameters. Using well-known concepts from surface science (such as surface tension, capillary effects, wettability, and contact angles) as inputs to mechanical models, the amount of effort required to handle micro-components is then predicted. Researchers and engineers involved in micromanipulation and precision assembly will find this a highly useful reference for microassembly system design and analysis.

Download or read book Surface Tension in Microsystems written by Pierre Lambert and published by Springer. This book was released on 2016-08-27 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes how surface tension effects can be used by engineers to provide mechanical functions in miniaturized products (1 mm). Even if precursors of this field such as Jurin or Laplace already date back to the 18th century, describing surface tension effects from a mechanical perspective is very recent.brThe originality of this book is to consider the effects of capillary bridges on solids, including forces and torques exerted both statically and dynamically by the liquid along the 6 degrees-of-freedom.brIt provides a comprehensive approach to various applications, such as capillary adhesion (axial force), centering force in packaging and micro-assembly (lateral force) and recent developments such as a capillary motor (torque).

Download or read book Electrical Interconnect of Components Transferred by Fluidic Microassembly Using Capillary Forces written by Karen Lemay Scott and published by . This book was released on 2003 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Capillary Force Microgripper for Microassembly Using Electrowetting on dielectric EWOD written by Abhay Vasudev and published by . This book was released on 2009 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Current MEMS devices are fabricated by monolithic micromachining in which all components are fabricated in one sequential process. Hybrid microsystems having complex 3-D geometries and multiple micro components cannot be manufactured using monolithic micromachining. In these situations, assembly of micron-sized parts is necessary. Gripping techniques using micro-grippers and manipulation tools are needed to accomplish micro-assembly tasks. Conventional mechanical grippers tend to scratch and indent micro components during assembly, which may destroy critical features on the components. Capillary and surface forces, which are dominant forces at the micro scale, can be utilized as the gripping mechanism to overcome drawbacks of mechanical grippers. Capillary grippers take advantage of capillary lifting forces evoling from a liquid bridge between two solid surfaces. In order to realize the pick-up, hold and release functions, the capillary lifting force needs to be varied and controlled dynamically. The capillary force needs to be greater than the weight of the micro component during the pick-up phase and hold phase so that the micro component can be positioned at the target location; subsequently, the lifting force needs to be reduced to a level where the weight of the micro component is greater than the lifting force to release the object. In this thesis, electrowetting is used to dynamically change the capillary forces to facilitate object pick-up and release. Electrowetting is a phenomenon that is used to dynamically change the contact angle of a liquid droplet at a liquid-solid interface by applying an electric potential. The liquid bridge capillary force, which is dependent on the contact angle the liquid bridge makes with the gripper surface, can thus be dynamically varied by electrowetting. The microgripper consists of interdigitated radial coplanar gold electrodes across which the driving voltage is applied and a thin hydrophobic insulator that separates the droplet from electrode. The higher the electric potential applied across the electrodes, the lower the contact angle of the liquid. The lifting force is at a maximum for the lowest contact angle and reduced to a minimum at the highest contact angle. In this thesis, first the change in contact angle of a de-ionized (DI) water droplet by electrowetting is demonstrated. The capillary lifting force of the microgripper is characterized using a digital electronic balance. Results indicate that electrowetting dynamically changes the capillary force evolved from a liquid bridge. The influence of liquid bridge height on lifting forces is also experimentally studied. Using a 0.8[[mu]m Teflon AF coating serving as insulation and also providing a hydrophobic surface, the microgripper is capable of picking up and releasing micro glass beads having a mass ranging from 77[mu]N to 136[mu]N. For the 136[mu]N glass bead, the pick-up and release voltages are 120V and 58V respectively. Experiments were conducted to determine the response time of electrowetting using a micro-liter droplet and the response time of the lifting force of liquid bridge. To reduce the driving voltage, a 0.5[mu]m Barium Strontium Titanate (BST) layer as the dielectric insulating layer is used. A thin coating of Teflon AF provides the hydrophobic surface. Experiments indicated that the use of BST as the dielectric insulation enables a low voltage microgripper, which can pick-up and release a 136[mu]N glass bead at 28V and 8V respectively. A study is carried out to determine the feasibility of use of room temperature ionic liquids (RTILs) as the liquid for microgripping using electrowetting. Although the total contact angle change for RTILs were found to be inferior to that of aqueous solutions, the properties of RTILs, such as high ionic conductivity, negligible volatility, non-flammability, thermal stability and usage in a wide temperature range offer distinct advantages over aqueous liquids for electrowetting applications. Further, the response time and lifting force of the RTIL based micrograpping is also characterized. The maximum lifting force generated was 140[mu]N."--Abstract.

Download or read book Analysis of Capillary Forces in Electrowetting and Precision Self Assembly written by Vivek Ramadoss and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Developments in micro and nano technology have great potential in many applications. Two applications that will be addressed in this work are self assembly of microdevices and Electrowetting in microfluidics. Capillary forces are the most critical factor in both of these techniques and need proper characterization. This thesis describes a detailed study of these forces and explains how they were utilized as an effective source of drive in high end applications. Self assembly is a promising alternative to conventional pick and place robotic assembly of micro components. Its benefits include parallel integration of parts with low equipment costs. Various approaches to self assembly have been demonstrated, yet demanding applications like assembly of micro-optical devices require increased positioning accuracy. This thesis proposes a new method for design of self assembly bonds that addresses this need. Current methods have zero force at the desired assembly position and low stiffness. The proposed method uses a substrate assembly feature to provide a high accuracy alignment guide to the part. The capillary bond region of the part and substrate are then modified to create a non-zero positioning force to maintain the part in the desired assembly position. Capillary force models show that this force aligns the part to the substrate assembly feature and reduces the sensitivity of part position to process variation. Thus, the new configuration analyzed proves substantial improvement in positioning accuracy of capillary self assembly. Guidelines are proposed for the design of an effective assembly bond using this new approach. Electrowetting is another application that has been successfully demonstrated as a means of drop manipulations in digital micro-fluidic devices. These demonstrations show that electrowetting actuation holds great promise, but there are also reports of erratic behavior and system degradation. While a method for electrowetting force measurement to track the degradation of the electrowetting response was demonstrated, this thesis analyzes some adverse effects in the electrowetting response due to variations during measurement of electrowetting forces, specially the variation of volume, the tilt in the part considered for measurements, and defective layer response.

Download or read book Fluidic Self assembly of Microfabricated Parts to Substrates Using Capillary Forces written by Uthara Srinivasan and published by . This book was released on 2001 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Robotic Microassembly written by Michael Gauthier and published by John Wiley & Sons. This book was released on 2011-01-14 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discover the latest models and methods for robotic microassembly from around the world This book presents and analyzes new and emerging models and methods developed around the world for robotic microassembly, a new and innovative way to produce better microsystems. By exploring everything from the physics of micromanipulation to microassembly to microhandling, it provides the first complete overview and review of this rapidly growing field. Robotic Microassembly is divided into three parts: Part One: Modeling of the Microworld Part Two: Handling Strategies Part Three: Robotic and Microassembly Together, these three parts feature eight chapters contributed by eight different authors. The authors, internationally recognized experts in the field of robotic microassembly, represent research laboratories in Asia, Europe, and North America. As a result, readers get a remarkable perspective on different approaches to robotic microassembly from around the world. Examples provided throughout the chapters help readers better understand how these different approaches work in practice. References at the end of each chapter lead to the primary literature for further investigation of individual topics. Robotic microassembly offers a new, improved way to manufacture high-performance microelectro-mechanical systems (MEMS). Therefore, any professional or student involved in microrobotics, micromechatronics, self-assembly or MEMS will find plenty of novel ideas and methods in this book that set the stage for new approaches to design and build the next generation of MEMS and microproducts.

Download or read book Microscale Surface Tension and Its Applications written by Pierre Lambert and published by MDPI. This book was released on 2019-10-21 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Building on advances in miniaturization and soft matter, surface tension effects are a major key to the development of soft/fluidic microrobotics. Benefiting from scaling laws, surface tension and capillary effects can enable sensing, actuation, adhesion, confinement, compliance, and other structural and functional properties necessary in micro- and nanosystems. Various applications are under development: microfluidic and lab-on-chip devices, soft gripping and manipulation of particles, colloidal and interfacial assemblies, fluidic/droplet mechatronics. The capillary action is ubiquitous in drops, bubbles and menisci, opening a broad spectrum of technological solutions and scientific investigations. Identified grand challenges to the establishment of fluidic microrobotics include mastering the dynamics of capillary effects, controlling the hysteresis arising from wetting and evaporation, improving the dispensing and handling of tiny droplets, and developing a mechatronic approach for the control and programming of surface tension effects. In this Special Issue of Micromachines, we invite contributions covering all aspects of microscale engineering relying on surface tension. Particularly, we welcome contributions on fundamentals or applications related to: Drop-botics: fluidic or surface tension-based micro/nanorobotics: capillary manipulation, gripping, and actuation, sensing, folding, propulsion and bio-inspired solutions; Control of surface tension effects: surface tension gradients, active surfactants, thermocapillarity, electrowetting, elastocapillarity; Handling of droplets, bubbles and liquid bridges: dispensing, confinement, displacement, stretching, rupture, evaporation; Capillary forces: modelling, measurement, simulation; Interfacial engineering: smart liquids, surface treatments; Interfacial fluidic and capillary assembly of colloids and devices; Biological applications of surface tension, including lab-on-chip and organ-on-chip systems.

Download or read book Capillary force Driven Self assembly of Silicon Microstructures written by Christopher James Morris and published by . This book was released on 2007 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book CAD Data Transfer for Solid Models written by Ernst G. Schlechtendahl and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Capillary Forces in Microassembly discusses the use of capillary forces as a gripping principle in microscale assembly. Clearly written and well-organized, this text brings together physical concepts at the microscale with practical applications in micromanipulation. Throughout this work, the reader will find a review of the existing gripping principles, elements to model capillary forces as well as descriptions of the simulation and experimental test bench developed to study the design parameters. Using well-known concepts from surface science (such as surface tension, capillary effects, wettability, and contact angles) as inputs to mechanical models, the amount of effort required to handle micro-components is then predicted. Researchers and engineers involved in micromanipulation and precision assembly will find this a highly useful reference for microassembly system design and analysis.

Download or read book Micro Assembly Technologies and Applications written by Svetan Ratchev and published by Springer Science & Business Media. This book was released on 2008-01-15 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Micro-assembly is a key enabling technology for cost effective manufacture of new generations of complex micro products. It is also a critical technology for retaining mdustrial capabilities in high labour cost areas such as Europe since up to 80% of the production cost in some industries is attributed directly to assembly processes. With the continuous trend for product miniaturisation, the scientific and technologi cal developments in micro-assembly are expected to have a significant long-term economic, demographic and social impact. A distinctive feature of the process is that surface forces are often dominant over gravity forces, which determines a number of specific technical challenges. Critical areas which are currently being addressed include development of assembly systems with high positional accuracy, micro gripping methods that take into ac count the adhesive surface forces, high precision micro-feeding techniques and mi cro-joining processes. Micro-assembly has developed rapidly over the last few years and all the pre dictions are that it will remain a critical technology for high value products in a number of key sectors such as healthcare, communications, defence and aerospace. The key challenge is to match the significant technological developments with a new generation of micro products that will establish firmly micro-assembly as a core manufacturing process.

Download or read book Capillary Forces Between Structured Substrates written by Emerson Jose de Souza and published by . This book was released on 2004 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Capillary Forces on Femtosecond Laser Micromachined Metallic Surfaces written by Jorge Lehr and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "In this PhD thesis, femtosecond laser micromachining was applied on titanium surfaces to produce homogeneous arrays of surface structures with the objective of studying their wetting behavior and the magnitude of capillary forces measured in a humid environment.The relevant machining parameters to control the formation of uniform arrays of surface structures were identified, and two types of surface microstructures covered with nanoscale roughness were produced in air. The two types of structures were found to result from different formation regimes, since only for one type a uniform energy input on the target surface was required to obtain a homogeneous array.Micromachining in pure oxygen, nitrogen and helium showed that the formation of these microstructures depends also on the environment: The chemical composition and optical properties of the surface and the cloud of ablated nanoparticles was identified to be responsible for the decrease of the effective energy input in a nitrogen environment. It was found that titanium-nitride (TiN) was formed on the surface during machining in nitrogen, while the surface chemistry, and hence the effective energy, were practically unchanged for oxygen and helium environments. Even though, it was possible to produce the two previously found types of microstructures, only oxygen was identified to allow the formation of highly uniform arrays.Wettability and capillary forces were measured with colloidal atomic force microscopy on the previously produced surfaces as well as on surfaces that carry only roughness on the nanoscale. Microstructured surfaces and these containing TiN were found to be hydrophobic, however exhibiting a high magnitude of capillary forces. The forces were limited on samples with only nanoscale roughness, which were machined in oxygen. At the same time these samples were hydrophobic and the least sensitive to an increase of the relative humidity in the environment." --

Download or read book Characterization of Capillary Forces During Liquid Metal Infiltration written by Maryam Bahraini Hasani and published by . This book was released on 2007 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microscale Surface Tension and Its Applications written by Massimo Mastrangeli and published by . This book was released on 2019 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: Building on advances in miniaturization and soft matter, surface tension effects are a major key to the development of soft/fluidic microrobotics. Benefiting from scaling laws, surface tension and capillary effects can enable sensing, actuation, adhesion, confinement, compliance, and other structural and functional properties necessary in micro- and nanosystems. Various applications are under development: microfluidic and lab-on-chip devices, soft gripping and manipulation of particles, colloidal and interfacial assemblies, fluidic/droplet mechatronics. The capillary action is ubiquitous in drops, bubbles and menisci, opening a broad spectrum of technological solutions and scientific investigations. Identified grand challenges to the establishment of fluidic microrobotics include mastering the dynamics of capillary effects, controlling the hysteresis arising from wetting and evaporation, improving the dispensing and handling of tiny droplets, and developing a mechatronic approach for the control and programming of surface tension effects. In this Special Issue of Micromachines, we invite contributions covering all aspects of microscale engineering relying on surface tension. Particularly, we welcome contributions on fundamentals or applications related to: Drop-botics: fluidic or surface tension-based micro/nanorobotics: capillary manipulation, gripping, and actuation, sensing, folding, propulsion and bio-inspired solutions; Control of surface tension effects: surface tension gradients, active surfactants, thermocapillarity, electrowetting, elastocapillarity; Handling of droplets, bubbles and liquid bridges: dispensing, confinement, displacement, stretching, rupture, evaporation; Capillary forces: modelling, measurement, simulation; Interfacial engineering: smart liquids, surface treatments; Interfacial fluidic and capillary assembly of colloids and devices; Biological applications of surface tension, including lab-on-chip and organ-on-chip systems. We expect novel as well as review contributions on all aspects of surface tension-based micro/nanoengineering. In line with Micromachines' policy, we also invite research proposals that introduce ideas for new applications, devices, or technologies.

Download or read book Assembly and Printing of Micro and Nano Objects written by Tobias Kraus and published by Cuvillier Verlag. This book was released on 2007-09-28 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials can be fabricated using particles as building blocks. Particles from various substances can thus be introduced into normally incompatible matrices, the unique properties of very small particles can be exploited, and different properties of different particles can be combined by mixing them in a material. Even very small particles are readily synthesized with high quality using modern chemical methods. Size ranges and material combinations that are usually difficult to attain can thus be achieved easily. In contrast to other methods, particle-based approaches allow us to fabricate regular structures at very small scales. The arrangement of particles in such structures is possible via self-assembly, which often is the only economical approach for small particle sizes. This work shows that certain conditions have to be fulfilled for self-assembly to be useful in technological applications. A concept is suggested that meets these requirements by combining templated self-assembly with adhesion-based particle handling. Using these methods, particles with diameters between 100 μm and 60 nm are assembled, transferred, and integrated on standard substrates without predefined surface structures. This produces materials with particles that retain their specific activities. Metal-coated microbeads provide electrical contact to semiconductors. Precisely arranged polymer beads protect sub-micrometer-scale parts of a surface in etch processes to yield metal nanodiscs or silicon nanorods. Gold nanocrystals remain catalytically active and nucleate the growth of silicon nanowires in a CVD process. Such nanocrystals are also optically active and sensitive to the refractive index of their immediate surroundings, which makes them useful in biological assays and similar analytical problems. In this work, we use several methods for the self-assembly of particles, all of which are based on topographical templates. Large particles (100 μm in diameter) can be assembled in a dry state from a fluidized bed. Smaller particles are generally handled as suspensions and have to be brought from the liquid phase onto a surface. To this end, we exploit capillary forces, which are present in all drying processes, and direct them using specialized surface topographies. The transport of the colloidal particles has to adjusted such as to create an accumulation zone with high local concentrations. This is done by tuning the substrate temperature (and thus, the evaporation rate), but also by using surfactants, which bias contact angle and stability of the suspension. We show that a large increase in local concentration is required when using small particles, which behave in a strongly stochastic manner owing to Brownian Motion. The passive handling of particles applied here is based on controlled particle adhesion in so-called adhesion cascades and reminds of the ink transfer in traditional printing. Different surfaces exert differently strong adhesion forces on the particles with which they come in contact. We modify and combine surfaces such that in every step the target substrate provides a stronger adhesion than the previous surface did. It becomes clear that the geometry of the particle-surface contact has a large influence on adhesion, so that mechanical properties of the surfaces influence particle adhesion, as their surface can conform to the particle's surface more or less. This dependence of adhesion on the contact geometry is strong enough even in small particles to enable the transfer of nanocrystals solely through contact area differences. The combination of self-assembly and transfer makes our method modular and compatible with existing techniques. We demonstrate this by its repeated application, which yields hierarchical structures containing different particle sizes. The method should also scale to very small particles, possibly using other self-assembly processes. We demonstrate one possible route for thiol molecules, which can be patterned in gradients by controlling their transport.

Download or read book Analytical and Experimental Investigation of Capillary Forces Induced by Nanopillars for Thermal Management Applications written by Conan Zhang and published by . This book was released on 2010 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents an analytical and experimental investigation into the capillary wicking limitation of an array of pillars. Commercial and nanopillar wicks are examined experimentally to assess the effects of micro and nanoscale capillary forces. By exerting a progressively higher heat flux on the wick, a maximum achievable mass flow was observed at the capillary limit. Through the balance of capillary and viscous forces, an ab initio analytical model is also presented to support the experimental data. Comparison of the capillary limit predicted by the analytical model and actual limit observed in experimental results are presented for three baseline wicks and two nanowicks.