Microrobots for wafer scale microfactory: design fabrication integration and control.

Future assembly technologies will involve higher automation levels, in order to satisfy increased micro scale or nano scale precision requirements. Traditionally, assembly using a top-down robotic approach has been well-studied and applied to micro-electronics and MEMS industries, but less so in nanotechnology. With the bloom of nanotechnology ever since the 1990s, newly designed products with new materials, coatings and nanoparticles are gradually entering everyone’s life, while the industry has grown into a billion-dollar volume worldwide. Traditionally, nanotechnology products are assembled using bottom-up methods, such as self-assembly, rather than with top-down robotic assembly. This is due to considerations of volume handling of large quantities of components, and the high cost associated to top-down manipulation with the required precision. However, the bottom-up manufacturing methods have certain limitations, such as components need to have pre-define shapes and surface coatings, and the number of assembly components is limited to very few. For example, in the case of self-assembly of nano-cubes with origami design, post-assembly manipulation of cubes in large quantities and cost-efficiency is still challenging. In this thesis, we envision a new paradigm for nano scale assembly, realized with the help of a wafer-scale microfactory containing large numbers of MEMS microrobots. These robots will work together to enhance the throughput of the factory, while their cost will be reduced when compared to conventional nano positioners. To fulfill the microfactory vision, numerous challenges related to design, power, control and nanoscale task completion by these microrobots must be overcome. In this work, we study three types of microrobots for the microfactory: a world’s first laser-driven micrometer-size locomotor called ChevBot，a stationary millimeter-size robotic arm, called Solid Articulated Four Axes Microrobot (sAFAM), and a light-powered centimeter-size crawler microrobot called SolarPede. The ChevBot can perform autonomous navigation and positioning on a dry surface with the guidance of a laser beam. The sAFAM has been designed to perform nano positioning in four degrees of freedom, and nanoscale tasks such as indentation, and manipulation. And the SolarPede serves as a mobile workspace or transporter in the microfactory environment

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

New Manufacturing Environments with Micro- and Nanorobotics

UIDB/04647/2020 UIDP/04647/2020The convergence of nano-, bio-, information, and cognitive sciences and technologies (NBIC) is advancing continuously in many societal spheres. This also applies to the manufacturing sector, where technological transformations in robotics push the boundaries of human–machine interaction (HMI). Here, current technological advances in micro- and nanomanufacturing are accompanied by new socio-economic concepts for different sectors of the process industry. Although these developments are still ongoing, the blurring of the boundaries of HMI in processes at the micro- and nano- level can already be observed. According to the authors, these new socio-technical HMIs may lead to the development of new work environments, which can also have an impact on work organization. While there is still little empirical evidence, the following contribution focuses on the question whether the “manufacturing (or working) life” using enhancement practices pushes the boundaries of HMI and how these effects enable new modes of working in manufacturing. Issues of standardization, acceleration of processes, and order-oriented production become essential for technological innovation in this field. However, these trends tend to lead to a “manufacturing life” in work environments rather than to new modes of work in industry.publishersversionepub_ahead_of_prin

Power-Scavenging MEMS Robots

This thesis includes the design, modeling, and testing of novel, power-scavenging, biologically inspired MEMS microrobots. Over one hundred 500-μm and 990-μm microrobots with two, four, and eight wings were designed, fabricated, characterized. These microrobots constitute the smallest documented attempt at powered flight. Each microrobot wing is comprised of downward-deflecting, laser-powered thermal actuators made of gold and polysilicon; the microrobots were fabricated in PolyMUMPs® (Polysilicon Multi-User MEMS Processes). Characterization results of the microrobots illustrate how wing-tip deflection can be maximized by optimizing the gold-topolysilicon ratio as well as the dimensions of the actuator-wings. From these results, an optimum actuator-wing configuration was identified. It also was determined that the actuator-wing configuration with maximum deflection and surface area yet minimum mass had the greatest lift-to-weight ratio. Powered testing results showed that the microrobots successfully scavenged power from a remote 660-nm laser. These microrobots also demonstrated rapid downward flapping, but none achieved flight. The results show that the microrobots were too heavy and lacked sufficient wing surface area. It was determined that a successfully flying microrobot can be achieved by adding a robust, light-weight material to the optimum actuator-wing configuration—similar to insect wings. The ultimate objective of the flying microrobot project is an autonomous, fully maneuverable flying microrobot that is capable of sensing and acting upon a target. Such a microrobot would be capable of precise lethality, accurate battle-damage assessment, and successful penetration of otherwise inaccessible targets

Concept, modeling and experimental characterization of the modulated friction inertial drive (MFID) locomotion principle:application to mobile microrobots

A mobile microrobot is defined as a robot with a size ranging from 1 in3 down to 100 µm3 and a motion range of at least several times the robot's length. Mobile microrobots have a great potential for a wide range of mid-term and long-term applications such as minimally invasive surgery, inspection, surveillance, monitoring and interaction with the microscale world. A systematic study of the state of the art of locomotion for mobile microrobots shows that there is a need for efficient locomotion solutions for mobile microrobots featuring several degrees of freedom (DOF). This thesis proposes and studies a new locomotion concept based on stepping motion considering a decoupling of the two essential functions of a locomotion principle: slip generation and slip variation. The proposed "Modulated Friction Inertial Drive" (MFID) principle is defined as a stepping locomotion principle in which slip is generated by the inertial effect of a symmetric, axial vibration, while the slip variation is obtained from an active modulation of the friction force. The decoupling of slip generation and slip variation also has lead to the introduction of the concept of a combination of on-board and off-board actuation. This concept allows for an optimal trade-off between robot simplicity and power consumption on the one hand and on-board motion control on the other hand. The stepping motion of a MFID actuator is studied in detail by means of simulation of a numeric model and experimental characterization of a linear MFID actuator. The experimental setup is driven by piezoelectric actuators that vibrate in axial direction in order to generate slip and in perpendicular direction in order to vary the contact force. After identification of the friction parameters a good match between simulation and experimental results is achieved. MFID motion velocity has shown to depend sinusoidally on the phase shift between axial and perpendicular vibration. Motion velocity also increases linearly with increasing vibration amplitudes and driving frequency. Two parameters characterizing the MFID stepping behavior have been introduced. The step efficiency ηstep expresses the efficiency with which the actuator is capable of transforming the axial vibration in net motion. The force ratio qF evaluates the ease with which slip is generated by comparing the maximum inertial force in axial direction to the minimum friction force. The suitability of the MFID principle for mobile microrobot locomotion has been demonstrated by the development and characterization of three locomotion modules with between 2 and 3 DOF. The microrobot prototypes are driven by piezoelectric and electrostatic comb drive actuators and feature a characteristic body length between 20 mm and 10 mm. Characterization results include fast locomotion velocities up to 3 mm/s for typical driving voltages of some tens of volts and driving frequencies ranging from some tens of Hz up to some kHz. Moreover, motion resolutions in the nanometer range and very low power consumption of some tens of µW have been demonstrated. The advantage of the concept of a combination of on-board and off-board actuation has been demonstrated by the on-board simplicity of two of the three prototypes. The prototypes have also demonstrated the major advantage of the MFID principle: resonance operation has shown to reduce the power consumption, reduce the driving voltage and allow for simple driving electronics. Finally, with the fabrication of 2 × 2 mm2 locomotion modules with 2 DOF, a first step towards the development of mm-sized mobile microrobots with on-board motion control is made

Design, evaluation, and control of nexus: a multiscale additive manufacturing platform with integrated 3D printing and robotic assembly.

Additive manufacturing (AM) technology is an emerging approach to creating three-dimensional (3D) objects and has seen numerous applications in medical implants, transportation, aerospace, energy, consumer products, etc. Compared with manufacturing by forming and machining, additive manufacturing techniques provide more rapid, economical, efficient, reliable, and complex manufacturing processes. However, additive manufacturing also has limitations on print strength and dimensional tolerance, while traditional additive manufacturing hardware platforms for 3D printing have limited flexibility. In particular, part geometry and materials are limited to most 3D printing hardware. In addition, for multiscale and complex products, samples must be printed, fabricated, and transferred among different additive manufacturing platforms in different locations, which leads to high cost, long process time, and low yield of products. This thesis investigates methods to design, evaluate, and control the NeXus, which is a novel custom robotic platform for multiscale additive manufacturing with integrated 3D printing and robotic assembly. NeXus can be used to prototype miniature devices and systems, such as wearable MEMS sensor fabrics, microrobots for wafer-scale microfactories, tactile robot skins, next generation energy storage (solar cells), nanostructure plasmonic devices, and biosensors. The NeXus has the flexibility to fixture, position, transport, and assemble components across a wide spectrum of length scales (Macro-Meso-Micro-Nano, 1m to 100nm) and provides unparalleled additive process capabilities such as 3D printing through both aerosol jetting and ultrasonic bonding and forming, thin-film photonic sintering, fiber loom weaving, and in-situ Micro-Electro-Mechanical System (MEMS) packaging and interconnect formation. The NeXus system has a footprint of around 4m x 3.5m x 2.4m (X-Y-Z) and includes two industrial robotic arms, precision positioners, multiple manipulation tools, and additive manufacturing processes and packaging capabilities. The design of the NeXus platform adopted the Lean Robotic Micromanufacturing (LRM) design principles and simulation tools to mitigate development risks. The NeXus has more than 50 degrees of freedom (DOF) from different instruments, precise evaluation of the custom robots and positioners is indispensable before employing them in complex and multiscale applications. The integration and control of multi-functional instruments is also a challenge in the NeXus system due to different communication protocols and compatibility. Thus, the NeXus system is controlled by National Instruments (NI) LabVIEW real-time operating system (RTOS) with NI PXI controller and a LabVIEW State Machine User Interface (SMUI) and was programmed considering the synchronization of various instruments and sequencing of additive manufacturing processes for different tasks. The operation sequences of each robot along with relevant tools must be organized in safe mode to avoid crashes and damage to tools during robots’ motions. This thesis also describes two demonstrators that are realized by the NeXus system in detail: skin tactile sensor arrays and electronic textiles. The fabrication process of the skin tactile sensor uses the automated manufacturing line in the NeXus with pattern design, precise calibration, synchronization of an Aerosol Jet printer, and a custom positioner. The fabrication process for electronic textiles is a combination of MEMS fabrication techniques in the cleanroom and the collaboration of multiple NeXus robots including two industrial robotic arms and a custom high-precision positioner for the deterministic alignment process

International Workshop on MicroFactories (IWMF 2012): 17th-20th June 2012 Tampere Hall Tampere, Finland

This Workshop provides a forum for researchers and practitioners in industry working on the diverse issues of micro and desktop factories, as well as technologies and processes applicable for micro and desktop factories. Micro and desktop factories decrease the need of factory floor space, and reduce energy consumption and improve material and resource utilization thus strongly supporting the new sustainable manufacturing paradigm. They can be seen also as a proper solution to point-of-need manufacturing of customized and personalized products near the point of need

Characterisation of the In-vivo Terahertz Communication Channel within the Human Body Tissues for Future Nano-Communication Networks.

PhDBody centric communication has been extensively studied in the past for a range of frequencies, however the need to reduce the size of the devices makes nano-scale technologies attractive for future applications. This opens up opportunities of applying nano-devices made of the novel materials, like carbon nano tubes (CNT), graphene and etc., which operate at THz frequencies and probably inside human bodies. With a brief introduction of nano-communications and review of the state of the art, three main contributions have been demonstrated in this thesis to characterise nano-scale body-centric communication at THz band: • A novel channel model has been studied. The path loss values obtained from the simulation have been compared with an analytical model in order to verify the feasibility of the numerical analysis. On the basis of the path loss model and noise model, the channel capacity is also investigated. • A 3-D stratified skin model is built to investigate the wave propagation from the under-skin to skin surface and the influence of the rough interface between different skin layers is investigated by introducing two detailed skin models with different interfaces (i.e.,3-D sine function and 3-D sinc function). In addition, the effects of the inclusion of the sweat duct is also analysed and the results show great potential of the THz waves on sensing and communicating. • Since the data of dielectric properties for biological materials at THz band are quite scarce, in collaboration with the Blizard Institute, London, UK, different human tissues such as skin, blood, muscle and etc. are planned to be measured with the THz Time Domain Spectroscopy (THz-TDS) system at Queen Mary University of London to enrich the database of electromagnetic parameters at the band of interest. In this chapter, collagen, the main constitution of skin was i mainly studied. Meanwhile, the measured results are compared with the simulated ones with a good agreement. Finally, a plan for further research activities is presented, aiming at widening and deepening the present understanding of the THz body-centric nano-communication channel, thus providing a complete characterisation useful for the design of reliable and efficient body centric nano-networks. iiChina Scholarship Council Queen Mary University of Londo

Mikrogreifer und aktive Mikromontagehilfsmittel mit integrierten Antrieben

Durch den laufenden Fortschritt in der Mikroelektronik und der Mikromechanik werden die Komponenten hybrider Mikrosysteme immer kleiner und oftmals empfindlicher. Die Handhabung dieser Submillimeter großen Einzelteile und die Montage zu komplexen Gesamtsystemen sind und bleiben eine besondere Herausforderung an die Aufbau- und Verbindungstechnik. Für diese steigenden Anforderungen im Bereich der Präzisions-Mikromontage wurden im Rahmen dieser Arbeit verschiedene mechanisch klemmende Mikrogreifer entworfen und deren Fertigungsprozesse hinsichtlich Batch-Fähigkeit optimiert. Je nach Handhabungsaufgabe kann zwischen Greifern mit unterschiedlichem Design, Material und Antrieb gewählt werden. Die Spanne möglicher Greifobjektgrößen reicht dabei von ca. 1 μm bis 500 μm. Zu den Antriebsprinzipien gehören unter anderem solche auf Basis von Formgedächtnislegierungen, deren Metallfolienaktoren mittels Ätz- oder Lasertechnik strukturiert und anschließend auf Waferlevel weiterprozessiert werden. Pneumatische Mikrozylinder bilden faltenbalgähnliche Kolbenstrukturen, die durch Anlegen von Über- oder Unterdruck die Greifergetriebe antreiben. Als drittes Antriebsprinzip wird die thermische Ausdehnung elektrisch beheizter Siliziumstrukturen genutzt, um Getriebemechaniken zu bewegen. Als Basismaterialien für die kinematischen Strukturen kommen hauptsächlich SU-8 Polymer und Silizium zum Einsatz. Neben festen Aktor-Getriebe-Kombinationen wurde auch ein Baukastensystem zur flexiblen Anpassung der Greifer an die Handhabungssituation entwickelt. Ergänzend zu den Greifstrukturen wurden pneumatische Mikromontagehilfsmittel für Desktop-Factories entwickelt. Sogenannte Mikrozentrifugalförderer versorgen den Montageroboter auf Abruf mit Glaskugeln von 300 μm Durchmesser. Darüber hinaus justieren Mikrospanneinheiten wenige Millimeter große Bauteile und fixieren diese für weitere Montageprozesse. Abschließend wurden die entwickelten Mikroelemente im Mikromontageprozess eines 3D-Kraftsensors erfolgreich eingesetzt.Due to the continuous progress in the fields of microelectronics and micromechanics, components of hybrid microsystems are becoming increasingly smaller and often increasingly fragile. The handling and assembling of these tiny parts to fabricate larger microsystems still remains a challenge in the field of packaging technologies. To keep up with these growing requirements in the scope of precision microassembly, several kinds of mechanical microgrippers have been developed and later optimized in terms of batch producibility. They are capable of handling component parts like microlenses, optical fibers and high precision balls for metrology styli or micro-ballbearings. The microparts can vary in size from 1 μm to 500 μm. Depending on the situation, different gripper materials, drives, and gripper designs can be used. Basic materials for the gripper gearings are SU-8 polymer and single crystal silicon. The actuation mechanisms are based either on shape memory alloys (SMA), pneumatic microcylinders or thermal expansion actuators. SMA actuators are shape formed from a cold rolled metal foil using wet chemical etching or laser structuring and then connected to mechanical structures on wafer level. Pneumatic cylinders are based on folded bellow structures that deflect when air pressure is applied. The third type of actuator uses the thermal expansion of heated silicon structures to drive the gripper gearing. In addition to permanent actuator-gearing-combinations, a flexible gripper construction kit was developed to provide a good adaptivity concerning the assembling situation. Two pneumatically driven auxiliary microtools were also developed to improve and to increase speed of assembling processes in desktop factories. The described microsystems are designed to function as centrifugal feeders for small glass balls or active clamping devices with small external dimensions. Both devices were successfully tested in an experimental setup for the assembly of a three-dimensional tactile force sensor