Integrated Microreactor for Chemical and Biochemical Applications

A completely integrated microreactor was developed that allows for the processing of very small amounts of chemical solutions. The entire system comprises several pumps and valves arranged in different branches as well as a mixing unit and a reaction chamber. The streaming path of each branch contains two valves and one pump each. The pumps are driven by piezoelectric elements mounted on thin glass membranes. Each pump is about 3.5 mm x 3.5 mm x 0.7 mm. A pumping rate up to 25 microliters per hour can be achieved. The operational voltage ranges between 40 and 200 V. A volume stroke up to 1.5 millimeter is achievable from the membrane structures. The valves are designed as passive valves. Sealing is by thin metal films. The dimension of a valve unit is 0.8 x 0.8. 07 mm. The ends of the separate streaming branches are arranged to meet in one point. This point acts as the beginning of a mixer unit which contains several fork-shaped channels. The arrangement of these channels allows for the division of the whole liquid stream into partial streams and their reuniting. A homogeneous mixing of solutions and/or gases can be observed after having passed about 10 of the fork elements. A reaction chamber is arranged behind the mixing unit to support the chemical reaction of special fluids. This unit contains heating elements placed outside of the chamber. The complete system is arranged in a modular structure and is built up of silicon. It comprises three silicon wafers bonded together by applying the silicon direct bonding technology. The silicon structures are made only by wet chemical etching processes. The fluid connections to the outside are realized using standard injection needles glued into v-shaped structures on the silicon wafers. It is possible to integrate other components, like sensors or electronic circuits using silicon as the basic material

Zellfreier biomolekularer Nanoaktor. Teilprojekt 2: Konzipierung und Untersuchung technischer Voraussetzungen linearmotorischer Nanometer-Antriebssysteme auf der Basis mechanochemischer Proteine vom Kinesintyp Abschlussbericht

SIGLEAvailable from TIB Hannover: F01B73 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Mikrohydraulisches Selbstreinigungsmodul fuer Parametersonden in biologischen Medien Abschlussbericht

Biofilm growth on sensors impairs the function of measuring instruments, so that high long-term stability is a key issue in measuring systems for aquatic conditions. The investigations focused on cleaning techniques suited for microsensors (cleaning modules, control), surface materials with low microfilm growth, and optimized cleaning intervals as a function of biofilm growth and composition.Durch Bewuchs von Sensoren wird die Genauigkeit und Funktionsfaehigkeit von Messgeraeten nach sehr kurzer Zeit stark beeinflusst. Durch die Verblockung eines Sensors mit Biofilmen wird der unmittelbare Kontakt zum Medium unterbrochen und die Messwerte durch die Vorgaenge in der Filmmatrix (Sauerstoffverbrauch, pH-Wert-Aenderungen, Erwaermung) verfaelscht. Die Erhoehung der Langzeitstabilitaet ist im Hinblick auf Wartungsaufwand und Energie- und Materialeinsparung eine der vordringlichsten Aufgaben in der Messtechnik aquatischer Umweltbedingungen. Gesucht werden - geeignete Reinigungsprinzipien fuer die Anwendung in der Mikrosensorik (Reinigungsmodule, Ansteuerung) - geeignete Oberflaechenmaterialien mit geringer Besiedlungsattraktivitaet - Optimierte Reinigungsintervalle in Abhaengigkeit von Wachstum und Zusammensetzung der Biofilme. (orig.)Available from TIB Hannover: F02B1099 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEForschungszentrum Juelich GmbH (Germany). Projekttraeger Biologie, Energie, Umwelt (BEO); Bundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman