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您的检索式：作者名="Erich Runge"
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| 1 | Highly efficient passive Tesla valves for microfluidic applications显示文摘A multistage optimization method is developed yielding Tesla valves that are efficient even at low flow rates,characteristic,e.g.,for almost all microfluidic systems,where passive valves have intrinsic advantages over active ones.We report on optimized structures that show a diodicity of up to 1.8 already at flow rates of 20μl s^(−1) corresponding to a Reynolds number of 36.Centerpiece of the design is a topological optimization based on the finite element method.It is set-up to yield easy-to-fabricate valve structures with a small footprint that can be directly used in microfluidic systems.Our numerical two-dimensional optimization takes into account the finite height of the channel approximately by means of a so-called shallow-channel approximation.Based on the threedimensionally extruded optimized designs,various test structures were fabricated using standard,widely available microsystem manufacturing techniques.The manufacturing process is described in detail since it can be used for the production of similar cost-effective microfluidic systems.For the experimentally fabricated chips,the efficiency of the different valve designs,i.e.,the diodicity defined as the ratio of the measured pressure drops in backward and forward flow directions,respectively,is measured and compared to theoretical predictions obtained from full 3D calculations of the Tesla valves.Good agreement is found.In addition to the direct measurement of the diodicities,the flow profiles in the fabricated test structures are determined using a two-dimensional microscopic particle image velocimetry(μPIV)method.Again,a reasonable good agreement of the measured flow profiles with simulated predictions is observed. | Sebastian Bohm Hai Binh Phi Ayaka Moriyama Erich Runge Steffen Strehle Jörg König Christian Cierpka Lars Dittrich | 2022 | Microsystems & Nanoengineering2022，8，5： | 0 |
| 2 | Long-lived electron emission reveals localized plasmon modes in disordered nanosponge antennas显示文摘We report long-lived,highly spatially localized plasmon states on the surface of nanoporous gold nanoparticles—nanosponges—with high excitation efficiency.It is well known that disorder on the nanometer scale,particularly in two-dimensional systems,can lead to plasmon localization and large field enhancements,which can,in turn,be used to enhance nonlinear optical effects and to study and exploit quantum optical processes.Here,we introduce promising,three-dimensional model systems for light capture and plasmon localization as gold nanosponges that are formed by the dewetting of gold/silver bilayers and dealloying.We study light-induced electron emission from single nanosponges,a nonlinear process with exponents of n≈5...7,using ultrashort laser pulse excitation to achieve femtosecond time resolution.The long-lived electron emission process proves,in combination with optical extinction measurements and finite-difference time-domain calculations,the existence of localized modes with lifetimes of more than 20 fs.These electrons couple efficiently to the dipole antenna mode of each individual nanosponge,which in turn couples to the far-field.Thus,individual gold nanosponges are cheap and robust disordered nanoantennas with strong local resonances,and an ensemble of nanosponges constitutes a meta material with a strong polarization independent,nonlinear response over a wide frequency range. | Germann Hergert Jan Vogelsang Felix Schwarz Dong Wang Heiko Kollmann Petra Groß Christoph Lienau Erich Runge Peter Schaaf | 2017 | Light(Science & Applications)2017，6，1： | 0 |
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