Konzeption eines rechnergestützten Konstruktionssystems für optomechatronische Baugruppen

With light signals in optical waveguides, very large amounts of data can be transmitted quickly and largely without interference. In the industrial and infrastructural sectors, e.g. in the automotive and aviation industries, demand is therefore increasing to further exploit this potential. What must development processes look like in order to integrate systems that transmit data by means of light? This is a central question for current research. So far, there is no modelling approach for the design of optomechatronic assemblies. The integration of optoelectronic components is an enormous challenge, since optical functions must be modelled in addition to the differences in the design procedures for mechatronic assemblies. This thesis deals with the conceptual design of a system for the computeraided development of optomechatronic assemblies, so-called 3D opto-MIDs. The aim of the work is to represent the interaction of the domains mechanics, electronics and optics in a holistic product development process. For this purpose, tasks such as the integration of electrical circuits as well as functionalities for the design of optical networks must be covered. For this purpose, it is first necessary to identify relevant sub-aspects and components to be realised in such a system. From these findings, a concept is developed of how the procedural flow of a corresponding system can look. By means of a prototypical implementation, a procedure for the design of the optomechatronic construction system is finally derived and evaluated.Mit Lichtsignalen in optischen Wellenleitern lassen sich schnell und weitgehend störungsfrei sehr große Datenmengen übertragen. Im industriellen und infrastrukturellen Bereich, z.B. in der Automobil- und Luftfahrtindustrie, steigt daher die Nachfrage, dieses Potential weiter auszuschöpfen. Wie müssen Entwicklungsprozesse aussehen, um Systeme, die Daten mittels Licht übertragen, zu integrieren? Dies ist eine zentrale Frage an die aktuelle Forschung. Bisher existiert kein Modellierungsansatz für die Konstruktion optomechatronischer Baugruppen. Die Integration optoelektronischer Komponenten stellt eine enorme Herausforderung dar, da neben den Unterschieden der Konstruktionsverfahren für mechatronische Baugruppen auch optische Funktionen modelliert werden müssen. Diese Arbeit behandelt den konzeptionellen Entwurf eines Systems zur rechnergestützten Entwicklung optomechatronischer Baugruppen, sogenannten 3D-Opto-MIDs. Ziel der Arbeit ist es, das Zusammenwirken der Domänen Mechanik, Elektronik und Optik in einem ganzheitlichen Produktentwicklungsprozess darzustellen. Dazu müssen Aufgaben wie die Integration von elektrischen Schaltungen, als auch Funktionalitäten zum Entwurf optischer Netze abgedeckt werden. Hierfür ist es zunächst notwendig relevante Teilaspekte und zu realisierende Komponenten eines solchen Systems zu identifizieren. Aus diesen Erkenntnissen wird ein Konzept erarbeitet, wie der prozedurale Ablauf eines entsprechenden Systems aussehen kann. Durch eine prototypische Implementierung wird eine Vorgehensweise zum Aufbau des optomechatronischen Konstruktionssystems abschließend abgeleitet und bewertet

Manufacturing of polymer optical waveguides using self-assembly effect on pre-conditioned 3D-thermoformed flexible substrates

Optical data communication is increasingly interesting for many applications in industrial processes. Therefore mass production is required to meet the requested price and lot sizes. Polymer optical waveguides show great promises to comply with price requirements while providing sufficient optical quality for short range data transmission. A high efficient fabrication technology using polymer materials could be able to create the essential backbone for 3D-optical data transmission in the future. The approach for high efficient fabrication technology of micro optics described in this paper is based on a self-assembly effect of fluids on preconditioned 3D-thermoformed polymer foils. Adjusting the surface energy on certain areas on the flexible substrate by flexographic printing mechanism is presented in this paper. With this technique conditioning lines made of silicone containing UV-varnish are printed on top of the foils and create gaps with the exposed substrate material in between. Subsequent fabrication processes are selected whether the preconditioned foil is coated with acrylate containing waveguide material prior or after the thermoforming process. Due to the different surface energy this material tends to dewet from the conditioning lines. It acts like regional barriers and sets the width of the arising waveguides. With this fabrication technology it is possible to produce multiple waveguides with a single coating process. The relevant printing process parameters that affect the quality of the generated waveguides are discussed and results of the produced waveguides with width ranging from 10 to 300 μm are shown. © 2017 SPIE.DF

Terahertz Spectroscopy: An investigation of the Structural Dynamics of Freeze-Dried Poly Lactic-co-glycolic Acid Microspheres

Biodegradable poly lactic-co-glycolic acid (PLGA) microspheres can be used to encapsulate peptide and offer a promising drug delivery vehicle. In this work we investigate the dynamics of PLGA microspheres prepared by freeze-drying and the molecular mobility at lower temperatures leading to the glass transition temperature, using temperature-variable terahertz time-domain spectroscopy (THz-TDS) experiments. The microspheres were prepared using a water-in-oil-in-water (w/o/w) double emulsion technique and subsequent freeze-drying of the samples. Physical characterisation was performed by morphology measurements, scanning electron microscopy, and helium pycnometry. The THz-TDS data show two distinct transition processes, $T_{\text{g},\beta}$ in the range of $167-219\,$K, associated with local motions, and $T_{\text{g},\alpha}$ in the range of $313-330\,$K associated with large-scale motions, for the microspheres examined. Using Fourier transform infrared spectroscopy measurements in the mid-infrared we were able to characterise the interactions between a model polypeptide, exendin-4, and the PLGA copolymer. We observe a relationship between the experimentally determined $T_{\text{g},\beta}$ and $T_{\text{g},\alpha}$ and free volume and microsphere dynamics.The authors acknowledge funding from AstraZeneca UK Limited (Medlmmune Limited) and the UK Engineering and Physical Sciences Research Council (EP/N022769/1). T.A.S. would like to thank the AJA-Karten Trust and the AIA-Kenneth Lindsay Trust for their financial support

Extremely high conductivity observed in the triple point topological metal MoP

Weyl and Dirac fermions have created much attention in condensed matter physics and materials science. Recently, several additional distinct types of fermions have been predicted. Here, we report ultra-high electrical conductivity in MoP at low temperature, which has recently been established as a triple point Fermion material. Here we show that the electrical resistivity is 6 n-ohm cm at 2 K with a large mean free path of 11 microns. de Haas-van Alphen oscillations reveal spin splitting of the Fermi surfaces. In contrast to noble metals with similar conductivity and number of carriers, the magnetoresistance in MoP does not saturate up to 9 T at 2 K. Interestingly, the momentum relaxing time of the electrons is found to be more than 15 times larger than the quantum coherence time. This difference between the scattering scales shows that momentum conserving scattering dominates in MoP at low temperatures.Comment: Updated texts and supplementar

Supporting data for: Non-Destructive Quantification of Fragmentation Within Tablets After Compression From Scattering Analysis of Terahertz Transmission Measurements

Raw data supporting the publication

Data of 'Terahertz Spectroscopy: An investigation of the Structural Dynamics of Freeze-Dried Poly Lactic-co-glycolic Acid Microspheres'

All data provided for the manuscript, this includes terahertz time-domain spectra over a range of temperature, mid-infrared FTIR spectra, DSC data and SEM images of microspheres used for drug delivery of protein drugs based on poly lactic-co-glycolic acid (PLGA) formulations

Impact of Immediate Release Film Coating on the Disintegration Process of Tablets

Pharmaceutical tablets are often coated with a layer of polymeric material to protect the drug from environmental degradation, facilitate the packaging process, and enhance patient compliance. However, the detailed effects of such coating layers on drug release are not well understood. To investigate this, flat-faced pure microcrystalline cellulose tablets with a diameter of 13 mm and a thickness between 1.5-1.6 mm were directly compressed, and a film coating layer with a thickness of 80-120 μm was applied to one face of these tablets. This tablet geometry and immediate release film coating were chosen as a model system to understand how the film coating interacts with the tablet core. The coating hydration and dissolution process was studied using terahertz pulsed imaging, while optical coherence tomography was used to capture further details on the swelling process of the polymer in the coated tablet. The study investigated the film coating polymer dissolution process and found the gelling of dissolving polymer restricted the capillary liquid transport in the core. These findings can help predict the dissolution of film coating within the typical range of thickness (30-40 μm) and potentially be extended to understand modified release coating formulations