A versatile microarray platform for capturing rare cells

Analyses of rare events occurring at extremely low frequencies in body fluids are still challenging. We established a versatile microarray-based platform able to capture single target cells from large background populations. As use case we chose the challenging application of detecting circulating tumor cells (CTCs) - about one cell in a billion normal blood cells. After incubation with an antibody cocktail, targeted cells are extracted on a microarray in a microfluidic chip. The accessibility of our platform allows for subsequent recovery of targets for further analysis. The microarray facilitates exclusion of false positive capture events by co-localization allowing for detection without fluorescent labelling. Analyzing blood samples from cancer patients with our platform reached and partly outreached gold standard performance, demonstrating feasibility for clinical application. Clinical researchers free choice of antibody cocktail without need for altered chip manufacturing or incubation protocol, allows virtual arbitrary targeting of capture species and therefore wide spread applications in biomedical sciences

A smart lamb-wave sensor system for the determination of fluid properties

Electrical Engineering, Mathematics and Computer Scienc

Rapid Prototyping of 3D Phononic Crystals using High-resolution Stereolithography Fabrication

AbstractWe present proof-of-concept devices to validate the suitability of high-resolution stereolithography fabrication, polymer material properties, and increased design freedom for realizing 3D phononic crystals. The maskless, single-step technology enables the fabrication of freeform 3D microstructures with high accuracy, which allows rapid prototyping of novel designs and leads to fast optimization cycles. Experimental results for devices with feature sizes down to 100 μm successfully indicate phononic band gap behavior, which is required for applications as sensor and microsystem structures

Miniature 3D Gas Chromatography Columns with Integrated Fluidic Connectors Using High-resolution Stereolithography Fabrication

AbstractIn this manuscript we report on design, fabrication, and characterization of miniature gas chromatography columns with arbitrary 3D geometry and integrated connectors as separation elements for a mobile ethylene sensor system. In contrast to planar microfabrication, these columns have been realized in a single step additive manufacturing process using high-resolution stereolithography printing. This maskless technology enables the combination of freeform 3D microstructures with packaging aspects in one bulk element. For applications in food monitoring, the columns were packed with Carbosieve®-SII particles as adsorbents. With the printed columns a minimal gas concentration of 35 ppb (3σ) ethylene can be detected. Retention times of 400 s for ethylene and 1035 s for water and no signal peak overlap show an improved separation capability