64 research outputs found
Potential energy threshold for nano-hillock formation by impact of slow highly charged ions on a CaF(111) surface
We investigate the formation of nano-sized hillocks on the (111) surface of
CaF single crystals by impact of slow highly charged ions. Atomic force
microscopy reveals a surprisingly sharp and well-defined threshold of potential
energy carried into the collision of about 14 keV for hillock formation.
Estimates of the energy density deposited suggest that the threshold is linked
to a solid-liquid phase transition (``melting'') on the nanoscale. With
increasing potential energy, both the basal diameter and the height of the
hillocks increase. The present results reveal a remarkable similarity between
the present predominantly potential-energy driven process and track formation
by the thermal spike of swift ( GeV) heavy ions.Comment: 10 pages, 2 figure
Synergism between particle-based multiplexing and microfluidics technologies may bring diagnostics closer to the patient
In the field of medical diagnostics there is a growing need for inexpensive, accurate, and quick high-throughput assays. On the one hand, recent progress in microfluidics technologies is expected to strongly support the development of miniaturized analytical devices, which will speed up (bio)analytical assays. On the other hand, a higher throughput can be obtained by the simultaneous screening of one sample for multiple targets (multiplexing) by means of encoded particle-based assays. Multiplexing at the macro level is now common in research labs and is expected to become part of clinical diagnostics. This review aims to debate on the “added value” we can expect from (bio)analysis with particles in microfluidic devices. Technologies to (a) decode, (b) analyze, and (c) manipulate the particles are described. Special emphasis is placed on the challenges of integrating currently existing detection platforms for encoded microparticles into microdevices and on promising microtechnologies that could be used to down-scale the detection units in order to obtain compact miniaturized particle-based multiplexing platforms
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