title: A Calibration-Free, Noncontact, Disposable Liquid Dispensing Cartridge Featuring an Online Process Control.
abstract: We present a noncontact liquid dispenser that uses a disposable cartridge for the calibration-free dosage of diverse biochemical reagents from the nanoliter to the microliter range. The dispensing system combines the advantages of a positive displacement syringe pump (responsible for defining the aliquot's volume with high accuracy) with a highly dynamic noncontact dispenser (providing kinetic energy to detach the liquid from the tip). The disposable, noncontact dispensing cartridge system renders elaborate washing procedures of tips obsolete. A noncontact sensor monitors the dispensing process to enable an online process control. To further increase confidence and reliability for particularly critical biomedical applications, an optional closed-loop control prevents malfunctions. The dispensing performance was characterized experimentally in the range of 0.25 to 10.0 µL using liquids of different rheological properties (viscosity 1.03-16.98 mPas, surface tension 30.49-70.83 mN/m) without adjusting or calibrating the actuation parameters. The precision ranged between a coefficient of variation of 0.5% and 5.3%, and the accuracy was below ±10%. The presented technology has the potential to contribute significantly to the improvement of biochemical liquid handling for laboratory automation in terms of usability, miniaturization, cost reduction, and safety.
authors: Laboratory for MEMS Applications, IMTEK-Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany stefan.bammesberger@imtek.de.
authors: Stefan Borja
authors: SB
authors: Bammesberger
authors: Laboratory for MEMS Applications, IMTEK-Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany.
authors: Imad
authors: I
authors: Malki
authors: Laboratory for MEMS Applications, IMTEK-Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany BioFluidix GmbH, Freiburg, Germany.
authors: Andreas
authors: A
authors: Ernst
authors: Laboratory for MEMS Applications, IMTEK-Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany HSG-IMIT-Institut für Mikro- und Informationstechnik, Freiburg, Germany.
authors: Roland
authors: R
authors: Zengerle
authors: Laboratory for MEMS Applications, IMTEK-Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany HSG-IMIT-Institut für Mikro- und Informationstechnik, Freiburg, Germany.
authors: Peter
authors: P
authors: Koltay
mesh_terms: D057205:Automation, Laboratory / Q000295:instrumentation*; D004867:Equipment Design; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted
keywords: calibration-free; laboratory automation; liquid handler; noncontact dispensing; online process control