Designing mechanosensitive molecules from molecular building blocks: a genetic algorithm-based approach

Single molecules can be used as miniaturized functional electronic components, when contacted by macroscopic electrodes. Mechanosensitivity describes a change in conductance for a certain change in electrode separation and is a desirable feature for applications such as ultrasensitive stress sensors. We combine methods of artificial intelligence with high-level simulations based on electronic structure theory to construct optimized mechanosensitive molecules from predefined, modular molecular building blocks. In this way, we overcome time-consuming, inefficient trial-and-error cycles in molecular design. We unveil the black box machinery usually connected to methods of artificial intelligence by presenting all-important evolutionary processes. We identify the general features that characterize well-performing molecules and point out the crucial role of spacer groups for increased mechanosensitivity. Our genetic algorithm provides a powerful way to search chemical space and to identify the most promising molecular candidates

Deterministic coupling of a single silicon-vacancy color center to a photonic crystal cavity in diamond

Deterministic coupling of single solid-state emitters to nanocavities is the key for integrated quantum information devices. We here fabricate a photonic crystal cavity around a preselected single silicon-vacancy color center in diamond and demonstrate modification of the emitters internal population dynamics and radiative quantum efficiency. The controlled, room-temperature cavity coupling gives rise to a resonant Purcell enhancement of the zero-phonon transition by a factor of 19, coming along with a 2.5-fold reduction of the emitter's lifetime

Nanotrench for nano and microparticle electrical interconnects

We present a simple and versatile patterning procedure for the reliable and reproducible fabrication of high aspect ratio (10 4 ) electrical interconnects that have separation distances down to 20 nm and lengths of several hundreds of microns. The process uses standard optical lithography techniques and allows parallel processing of many junctions, making it easily scalable and industrially relevant. We demonstrate the suitability of these nanotrenches as electrical interconnects for addressing micro and nanoparticles by realizing several circuits with integrated species. Furthermore, low impedance metal-metal low contacts are shown to be obtained when trapping a single metal-coated microsphere in the gap, emphasizing the intrinsic good electrical conductivity of the interconnects, even though a wet process is used. Highly resistive magnetite-based nanoparticles networks also demonstrate the advantage of the high aspect ratio of the nanotrenches for providing access to electrical properties of highly resistive materials, with leakage current levels below 1 pA. © 2010 IOP Publishing Ltd

Pointshop 3D: An interactive system for point-based surface editing

We present a system for interactive shape and appearance editing of 3D point-sampled geometry. By generalizing conventional 2D pixel editors, our system supports a great variety of different interaction techniques to alter shape and appearance of 3D point models, including cleaning, texturing, sculpting, carving, filtering, and resampling. One key ingredient of our framework is a novel concept for interactive point cloud parameterization allowing for distortion minimal and aliasing-free texture mapping. A second one is a dynamic, adaptive resampling method which builds upon a continuous reconstruction of the model surface and its attributes. These techniques allow us to transfer the full functionality of 2D image editing operations to the irregular 3D point setting. Our system reads, processes, and writes point-sampled models without intermediate tesselation. It is intended to complement existing low cost 3D scanners and point rendering pipelines for efficient 3D content creation

Perspective accurate splatting

We present a novel algorithm for accurate, high quality point rendering, which is based on the formulation of splatting using homogeneous coordinates. In contrast to previous methods, this leads to perspective correct splat shapes, avoiding artifacts such as holes caused by the affine approximation of the perspective projection. Further, our algorithm implements the EWA resampling filter, hence providing high image quality with anisotropic texture filtering. We also present an extension of our rendering primitive that facilitates the display of sharp edges and corners. Finally, we describe an efficient implementation of the entire point rendering pipeline using vertex and fragment programs of current GPUs

Modelling and Study of a Microwave Plasma Source for High-rate Etching

[EN] The aim of this study is to investigate and to optimize an existing microwave-powered remote plasma source (RPS) with respect to the etching rate and gas temperature and to simplify the setup to save production costs. To achieve these goals, a FEM-based model of the RPS has been developed in order to investigate the microwave coupling into the plasma chamber and the microwave field distribution as well as the plasma itself. Different examples of FEM-based microwave simulations at different conditions and their experimental validations will be presented.Pauly, S.; Schulz, A.; Walker, M.; Gorath, K.; Baumgärtner, K.; Tovar, G. (2019). Modelling and Study of a Microwave Plasma Source for High-rate Etching. En AMPERE 2019. 17th International Conference on Microwave and High Frequency Heating. Editorial Universitat Politècnica de València. 35-42. https://doi.org/10.4995/AMPERE2019.2019.9757OCS354