Piezoelectric titanium based microfluidic pump and valves for implantable medical applications

Medical devices often require precise movement of fluids. Automated implants with no need for manual handling improve patient care significantly. However, existing microfluidic devices do not fulfil the necessary specifications of size, safety, hermetic sealing, and artefact free medical imaging, as well as energy efficiency combined with adapted fluidic properties. In this work we designed, manufactured, and experimentally evaluated three piezoelectric microfluidic devices for implant automation: a diaphragm pump, a normally closed valve, and a normally open valve. All devices are made of titanium, minimizing the risk of artefacts in medical imaging. They have similar form factors and use the same actuation method. For the later, a specific mounting process of the piezo actuator enables outstanding fluidic performance during experimental evaluations. The titanium micropumps show a maximal flow of (14 ± 2.2) ml/min and pressure build-up of 75 kPa. The normally closed valve’s leakage rates are extremely low with less than 1 μL/min. Detailed investigations further include the actuator stroke, a lifetime study for normally open valves, and a numerical and experimental evaluation of the normally closed valve’s spring foil. The introduced titanium technology platform is ideally suited for system integration accounted for by the use of the same actuation principle and the similar form factor and a simple design. The development of small, smart, and energy efficient implants for improved treatment is possible based on the introduced platform

Experimentelle Charakterisierung und Simulation von piezoelektrischen Mikropumpen und Mikroventilen aus Titan

This dataset contains experimental data as a characterisation of piezoelectric micropumps and microvalves. Measurement data includes the actuator stroke measured using white light profilometry, as well as fluidic measurements of generated flow, passive flow, and leakage measured using coriflow flowmeters. Flow measurement data of normally open valves before and after 10^6 actuation cycles is supplied. An ANSYS 2019 R1 project file is given as part of an evaluation of a normally closed valve's spring foil. Associated with the simulation is experimental data of the pressure-dependant stroke of the normally closed valve's spring foil.The dataset contains .dat files for fluidic measurements; .txt files for stroke measurements; and an ANSYS 2019 R1 project file. Data of micropumps, NO microvalves, NC microvalves, and simulation files are collected in separate zip folders, respectively. The tabular data can be evaluated using EXCEL or Python. Simulation data can be used with ANSYS Version 2019 R1 or higher

Interferometric broadband Fourier spectroscopy with a partially coherent gas-discharge extreme ultraviolet light source

Extreme ultraviolet (EUV) spectroscopy is a powerful tool for studying fundamental processes in plasmas as well as for spectral characterization of EUV light sources and EUV optics. However, a simultaneous measurement covering a broadband spectral range is difficult to realize. Here, we propose a method for interferometric broadband Fourier spectroscopy connecting soft x ray and visible spectral ranges with moderate spectral resolution. We present an analytical model to recover the spectrum from a double-slit interferogram. We apply our model for spectral characterization of a partially coherent gas-discharge EUV light source operated with different gases in the spectral range between 10 and 110 nm wavelengths. Our approach allows a simple and fast broadband spectroscopy with fully or partially spatially coherent light sources, for instance, to characterize out-of-band radiation in EUV lithography applications