Tissue engineering is a field devoted to the design and creation of replacement tissues with the ultimate goal of one day providing replacement organs. Traditional strategies to accomplish this through the bulk seeding of cells onto a single monolithic porous bio-scaffold are unable to realise a precise architecture, thus the inability to mimic the cells natural micro-environment found within the body. Bio-printing approaches are the current state of the art with the ability to accurately mimic the complex 3D hierarchical structure of tissue. However, a functional construct also requires high strength to provide adequate support in load bearing applications such as bone and cartilage tissue engineering, and to maintain the open geometry of a large intricate channel network, which is crucial for the transport of nutrients and wastes. Typical approaches utilise materials which have processing parameters more amendable for cell incorporation, thus they can be simultaneously deposited with scaffolding material. However, the resulting construct is typically of low strength. This thesis explores the automation of a printing and “tissue assembly” process with the ability to incorporate delicate cell aggregates or spheroids within a high strength bio-scaffold requiring harsh processing parameters, at precise locations. The 3D printed bio-scaffold has a lattice architecture which enables a frictional fit to be formed between the particle and scaffold, thus preventing egress. To achieve this the pore must be expanded before the delivery of a single 1mm particle. Novel subsystems were developed to automate this process and provide the ability to achieve scalable, flexible, complex constructs with accurate architecture. A system architecture employing the benefits of modularity was devised. The main subsystems developed were the singulation device, to ensure the separation of a single particle; the injection device, to deliver and seed particles into the scaffold, and the control system, to facilitate the operation of the devices. Three generations of singulation devices have been developed ranging from mechanical to fluid manipulation methods alone. The first prototype utilised mechanical methods, with simple control methods. However the inability to correctly position the lead particle within the singulation chamber, resulted in damage to the test alginate particles. In the second prototype a fully fluidics based device utilised two trapping sites to capture the leading particles. Singulation success rates of up to 88% was achieved. Higher rates were limited by the trapped particle’s interaction with the lagging particles during capture. In a similar concept to the second prototype, the third prototype utilised only a single trapped particle, and achieved much higher throughput, and 100% singulation accuracy. The injection device, utilised a conical expanding rod within a thin outer sheath. It was able to expand the pore, with minimal damage to the scaffold, providing an unobstructed path for the delivery of the particle into the pore. A decentralised control system was devised to integrate the process operation for the electro-mechanical devices. Separate microcontrollers were able to sense, interact and communicate with one another, and the master control PC, to execute specific tasks to automate the process. The development of systems to automate the process has addressed the ability to accurately incorporate delicate cells with a high strength bio-scaffold, and will enable the realisation and investigation of intricate complex constructs, unachievable with current manual processes. Thus features found within the body may be more closely mimicked and functionalised, which may provide the necessary signals, micro-environment and infrastructure to correctly regulate the formation of complex functional tissue, supported by the adequate mass transport of nutrients and wastes. This may one day lead to 3D printing or assembly of viable replacement tissue, accurate in vitro model systems for laboratory testing, or even whole organs.

Für die hochgenaue Lagezuordnung von Mikrobauteilen in Mikromontageprozessen fehlen bislang Lösungen für eine greifernahe oder greiferintegrierte Winkelfeinstellung. In der vorliegenden Arbeit werden Einflussfaktoren und Auswirkungen lokaler Restfehler auf die Lagezuordnung im Mikromontageprozess diskutiert und Strategien für eine Lagekorrektur am Mikrobauteil unmittelbar im Montageprozess abgeleitet. Im Mittelpunkt steht die Herleitung und Erforschung eines kinematischen Grundprinzips für eine greiferintegrierte Winkelfein- stellung. Eine durch Simulation des Verformungsverhaltens optimierte räumliche Biegegelenk- struktur gestattet das spielfreie Einstellen und Halten kleinster Winkellagen im Winkel- sekundenbereich um einen auf dem gegriffenen Bauteil liegenden Drehpunkt. Das Funktions- prinzip dieses Übertragungsgliedes bildet die Grundlage für einen neuartigen modular aufgebauten Präzisionsgreifertyp. Die Wirksamkeit der greiferintegrierten Winkelfein- stellung wird an einem Anlagendemonstrator zur hochgenauen Bestückung optischer Leiter- platten mit elektrisch-optischen Sende- und Empfangsmodulen nachgewiesen. Mithilfe des neu entwickelten modularen Präzisionsgreifers lassen sich Mikromontagestrategien mit prozessintegrierter bauteilindividueller Lagekorrektur umsetzen. Montagegenauigkeiten unter 5 µm können damit besser anlagentechnisch beherrscht werden, ohne dass ein zusätzliches manuelles Feinausrichten notwendig ist. / For state-of-the-art micro assembly processes with high precision alignment of micro components, solutions for a precise angle adjustment near by or integrated into a gripper are not provided yet. In this PhD thesis influencing factors and implications of local alignment failures are will be discussed and correction strategies directly in the assembling flow are will be deduced. In the central point of the PhD thesis the derivation and investigation of a novel kinematic principle for a gripper integrated angle adjustment are located. A flexure hinge structure could be designed that enables a free from backlash adjusting and fixing of angles in a size of less angular seconds whereas the center of rotation is located on the gripped part. The hinge structure was optimized by simulating the deformation behavior. The functional principle of this mechanism presents the base of a novel type of a modular precision gripper. The effectivity of the gripper integrated angle adjustment was verified at the application of high precision mounting of electric-optical circuit boards with light coupling transmitter and receiver modules. With the help of the new developed precision gripper micro assembly strategies could be realized basing on in-process alignment corrections of the individual gripped micro part. Assembly accuracies below 5 microns could be achieved plantspecific in a better way without additional manual steps for fine positioning.

Für die hochgenaue Lagezuordnung von Mikrobauteilen in Mikromontageprozessen fehlen bislang Lösungen für eine greifernahe oder greiferintegrierte Winkelfeinstellung. In der vorliegenden Arbeit werden Einflussfaktoren und Auswirkungen lokaler Restfehler auf die Lagezuordnung im Mikromontageprozess diskutiert und Strategien für eine Lagekorrektur am Mikrobauteil unmittelbar im Montageprozess abgeleitet. Im Mittelpunkt steht die Herleitung und Erforschung eines kinematischen Grundprinzips für eine greiferintegrierte Winkelfein- stellung. Eine durch Simulation des Verformungsverhaltens optimierte räumliche Biegegelenk- struktur gestattet das spielfreie Einstellen und Halten kleinster Winkellagen im Winkel- sekundenbereich um einen auf dem gegriffenen Bauteil liegenden Drehpunkt. Das Funktions- prinzip dieses Übertragungsgliedes bildet die Grundlage für einen neuartigen modular aufgebauten Präzisionsgreifertyp. Die Wirksamkeit der greiferintegrierten Winkelfein- stellung wird an einem Anlagendemonstrator zur hochgenauen Bestückung optischer Leiter- platten mit elektrisch-optischen Sende- und Empfangsmodulen nachgewiesen. Mithilfe des neu entwickelten modularen Präzisionsgreifers lassen sich Mikromontagestrategien mit prozessintegrierter bauteilindividueller Lagekorrektur umsetzen. Montagegenauigkeiten unter 5 µm können damit besser anlagentechnisch beherrscht werden, ohne dass ein zusätzliches manuelles Feinausrichten notwendig ist. / For state-of-the-art micro assembly processes with high precision alignment of micro components, solutions for a precise angle adjustment near by or integrated into a gripper are not provided yet. In this PhD thesis influencing factors and implications of local alignment failures are will be discussed and correction strategies directly in the assembling flow are will be deduced. In the central point of the PhD thesis the derivation and investigation of a novel kinematic principle for a gripper integrated angle adjustment are located. A flexure hinge structure could be designed that enables a free from backlash adjusting and fixing of angles in a size of less angular seconds whereas the center of rotation is located on the gripped part. The hinge structure was optimized by simulating the deformation behavior. The functional principle of this mechanism presents the base of a novel type of a modular precision gripper. The effectivity of the gripper integrated angle adjustment was verified at the application of high precision mounting of electric-optical circuit boards with light coupling transmitter and receiver modules. With the help of the new developed precision gripper micro assembly strategies could be realized basing on in-process alignment corrections of the individual gripped micro part. Assembly accuracies below 5 microns could be achieved plantspecific in a better way without additional manual steps for fine positioning.