Publications
Morten Hannibal Madsen, Poul-Erik Hansen, Imaging scatterometry for flexible measurements of patterned areas, Optics Express 24(2):1109 · January 2016.
Abstract: Characterization of micro/nano-textured surfaces is time consuming using scanning probe and electron microscopy techniques. Scatterometry, where the intensity of scattered light is used as a 'fingerprint' to reconstruct a surface, is a fast and robust method for characterization of gratings. However, most scatterometry techniques are measuring the averaged signal over an area equal to the spot size of the light source. In this paper we present the imaging scatterometry technique, which is capable of locally measuring topographic parameters of gratings spanning an area down to a few mu m(2) with nm accuracy. The imaging scatterometer can easily find areas of interest on the cm scale and measure multiple segments simultaneously. We demonstrate two imaging scatterometers, one built into an optical microscope and one in a split configuration. The two scatterometers are targeted characterization of mm(2) and cm(2) areas, respectively, and both setups are validated using nano-textured samples. (C) 2016 Optical Society of America.
C.E. Poulsen, K. Kistrup, N. K. Andersen, R.Taboryski, M. F. Hansen, A. Wolff, Laser ablated micropillar energy directors for ultrasonic welding of microfluidic systems, J. Micromech. Microeng. Volume 26, Number 6, 2016.
Abstract: We present a new type of energy director (ED) for ultrasonic welding of microfluidic systems. These micropillar EDs are based on the replication of cone like protrusion structures introduced using a pico-second laser and may therefore be added to any mould surface accessible to a pico-second laser beam. The technology is demonstrated on an injection moulded microfluidic device featuring high-aspect ratio (h × w = 2000 μm × 550 μm) and free-standing channel walls, where bonding is achieved with no detectable channel deformation. The bonding strength is similar to conventional EDs and the fabricated system can withstand pressures of over 9.5 bar.