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Biomedical subjects

M Fialkowski

Publications and source records attributed to M Fialkowski.

5 recordsLinked to original sources
PubMed2006

Microchameleons: nonlinear chemical microsystems for amplification and sensing.

In biological systems, the coupling of nonlinear biochemical kinetics and molecular transport enables functional sensing and "signal" amplification across many length scales. Drawing on biological inspiration, we describe how artificial reaction-diffusion (RD) microsystems can provide a basis for sensing applications, capable of amplifying micro- and nanoscopic events into macroscopic visual readouts. The RD applications reviewed here are based on a novel experimental technique, WETS for Wet Stamping, which offers unprecedented control over RD processes in microscopic and complex geometries. It is discussed how RD can be used to sense subtle differences in the thickness and/or absorptivity of thin absorptive films, amplify macromolecular phase transitions, detect the presence and quality of self-assembled monolayers, and provide dynamic spatiotemporal readouts of chemical "metabolites."

Absorption↗
PubMed2005

Wet stamping of microscale periodic precipitation patterns.

Although periodic precipitation (PP) phenomena have long attracted scientific interest, their study has been limited to macroscopic systems and simple geometries. An experimental method was developed that allows the generation of highly regular, microscopic PP patterns of arbitrary geometries. Generic scaling laws were established that related the morphologies and topographies of the PP patterns to the geometrical parameters of the system. It was possible to control PP at the level of stochastic phenomena and thus to induce micropatterns of desired chiralities and to control the propagation of defects in them. A 3D nucleation-and-growth model was developed that faithfully reproduced the patterns observed in experiments.

Journal Article↗
PubMed2004

Absorption of water by thin, ionic films of gelatin.

This paper discusses absorption of water by thin, dry films of gelatin. Experiments using a wet-stamping technique were performed to characterize water uptake in terms of (i) equilibrium profiles of the water density inside the gel and (ii) the kinetics of water absorption. It was found that, in contrast to pure gelatin films, which absorb water approximately uniformly, films of gelatin doped with ionic additives have exponentially decaying equilibrium water profiles. The process of water absorption by both doped and undoped gels was described by a theoretical model based on the minimization of grand potential functional. The results of this model are in agreement with the experiment.

Gelatin↗
PubMed2001

Scaling of the Euler characteristic, surface area, and curvatures in the phase separating or ordering systems.

We present robust scaling laws for the Euler characteristic and curvatures applicable to any symmetric system undergoing phase separating or ordering kinetics. We apply it to the phase ordering in a system of the nonconserved scalar order parameter and find three scaling regimes. The appearance of the preferred nonzero curvature of an interface separating +/- domains marks the crossover to the late stage regime characterized by the Lifshitz-Cahn-Allen scaling.

Journal Article↗