Publications (141) View all
-
Article: EndoMediskop. Trans-Endoscopic Microinjection for Flexible Endoscopy.
Biomedizinische Technik/Biomedical Engineering 08/2012; · 0.53 Impact Factor -
Article: Sub-μm structured lotus surfaces manufacturing
[show abstract] [hide abstract]
ABSTRACT: Sub-μm structured surfaces allow modifying the behavior of polymer films or components. Especially in micro-fluidics a lotus-like characteristic is requested for many applications. Structure details with a high aspect ratio are necessary to decouple the bottom and the top of the functional layer. Unlike to stochastic methods, patterning with a LIGA-mold insert it is possible to structure surfaces very uniformly or even with controlled variations (e.g., with gradients). In this paper we present the process chain to realize polymer sub-μm structures with minimum lateral feature size of 400nm and up to 4μm high.Microsystem Technologies 04/2012; 15(8):1327-1333. · 0.93 Impact Factor -
Conference Proceeding: A Calibration-Free, Disposable, Non-Contact Reagent Dosing Cartridge for the Sub-ul Range
MFHS 2012 Proceedings; 01/2012 -
Article: Noncontact Determination of Velocity and Volume of Nanoliter Droplets on the Fly
[show abstract] [hide abstract]
ABSTRACT: We present a sensor for measuring volume and velocity of dispensed nanoliter droplets in a noncontact manner on the fly. The sensor-setup has a total thickness of 3.2 mm and can easily be mounted underneath any given nanoliter dispenser for continuous online monitoring of its dispensing performance. The principle is based on the interaction of dispensed single droplets of sample liquid passing the electric field of an open plate capacitor. The effect depends on droplet parameters like volume, velocity, and dielectric constant and is discussed in the paper. The presented data analysis enables a velocity independent volume determination of water droplets in the range from 26 to 82 nl with an accuracy of 3 nl. The sensor signal is sensitive to the alignment of the flight path of the nanoliter droplets within the 1.2-mm wide open capacitor and can lead to systematic volume errors of up to ΔV ~ 12 nl. The impact of different dielectric constants can only be differentiated for very high variations; thus, the sensor needs to be calibrated to the different types of liquids.IEEE Sensors Journal 09/2011; · 1.52 Impact Factor -
Conference Proceeding: Towards a microfluidic dispenser chip for printing of single cells
[show abstract] [hide abstract]
ABSTRACT: We present a microfluidic dispenser chip for printing of single-particles or cells onto a substrate. The dispenser chip, fabricated in silicon/glass technology features hydrodynamic flow focusing to transport single particles in a fluid channel and a drop-on-demand dispensing mechanism to eject single particles confined in a free flying droplet of about 200 pl volume. A computer vision-based approach is employed to detect single particles prior to dispensing. We have evaluated the system experimentally by successfully depositing single polystyrene-beads on glass slides with a yield of 92%.Micro Electro Mechanical Systems (MEMS), 2011 IEEE 24th International Conference on; 02/2011
