@article {2014,
	title = {A robotic crawler exploiting directional frictional interactions: experiments, numerics, and derivation of a reduced model},
	journal = {Proceedings of the Royal Society A 470, 20140333 (2014)},
	year = {2014},
	publisher = {Royal Society Publishing},
	abstract = {We present experimental and numerical results for a model crawler which is able to extract net positional changes from reciprocal shape changes, i.e. {\textquoteleft}breathing-like{\textquoteright} deformations, thanks to directional, frictional interactions with a textured solid substrate, mediated by flexible inclined feet. We also present a simple reduced model that captures the essential features of the kinematics and energetics of the gait, and compare its predictions with the results from experiments and from numerical simulations.},
	doi = {10.1098/rspa.2014.0333},
	author = {Giovanni Noselli and Antonio DeSimone}
}
@article {2012,
	title = {Reverse engineering the euglenoid movement},
	journal = {Proceedings of the National Academy of Sciences of the United States of America. Volume 109, Issue 44, 30 October 2012, Pages 17874-17879},
	year = {2012},
	abstract = {Euglenids exhibit an unconventional motility strategy amongst unicellular eukaryotes, consisting of large-amplitude highly concerted deformations of the entire body (euglenoid movement or metaboly). A plastic cell envelope called pellicle mediates these deformations. Unlike ciliary or flagellar motility, the biophysics of this mode is not well understood, including its efficiency and molecular machinery. We quantitatively examine video recordings of four euglenids executing such motions with statistical learning methods. This analysis reveals strokes of high uniformity in shape and pace. We then interpret the observations in the light of a theory for the pellicle kinematics, providing a precise understanding of the link between local actuation by pellicle shear and shape control. We systematically understand common observations, such as the helical conformations of the pellicle, and identify previously unnoticed features of metaboly. While two of our euglenids execute their stroke at constant body volume, the other two exhibit deviations of about 20\% from their average volume, challenging current models of low Reynolds number locomotion. We find that the active pellicle shear deformations causing shape changes can reach 340\%, and estimate the velocity of the molecular motors. Moreover, we find that metaboly accomplishes locomotion at hydrodynamic efficiencies comparable to those of ciliates and flagellates. Our results suggest new quantitative experiments, provide insight into the evolutionary history of euglenids, and suggest that the pellicle may serve as a model for engineered active surfaces with applications in microfluidics.},
	keywords = {microswimmers},
	doi = {10.1073/pnas.1213977109},
	url = {http://hdl.handle.net/1963/6444},
	author = {Marino Arroyo and Luca Heltai and Daniel Mill{\'a}n and Antonio DeSimone}
}
@article {2010,
	title = {The role of membrane viscosity in the dynamics of fluid membranes},
	number = {SISSA;55/2010/M},
	year = {2010},
	abstract = {Fluid membranes made out of lipid bilayers are the fundamental separation structure in eukaryotic cells. Many physiological processes rely on dramatic shape and topological changes (e.g. fusion, fission) of fluid membrane systems. Fluidity is key to the versatility and constant reorganization of lipid bilayers. Here, we study the role of the membrane intrinsic viscosity, arising from the friction of the lipid molecules as they rearrange to accommodate shape changes, in the dynamics of morphological changes of fluid vesicles. In particular, we analyze the competition between the membrane viscosity and the viscosity of the bulk fluid surrounding the vesicle as the dominant dissipative mechanism. We consider the relaxation dynamics of fluid vesicles put in an out-of-equilibrium state, but conclusions can be drawn regarding the kinetics or power consumption in regulated shape changes in the cell. On the basis of numerical calculations, we find that the dynamics arising from the membrane viscosity are qualitatively different from the dynamics arising from the bulk viscosity. When these two dissipation mechanisms are put in competition, we find that for small vesicles the membrane dissipation dominates, with a relaxation time that scales as the size of the vesicle to the power 2. For large vesicles, the bulk dissipation dominates, and the exponent in the relaxation time vs. size relation is 3.},
	url = {http://hdl.handle.net/1963/3930},
	author = {Marino Arroyo and Antonio DeSimone and Luca Heltai}
}
@article {2009,
	title = {Relaxation dynamics of fluid membranes},
	journal = {Phys. Rev. E  79 (2009) 031915},
	year = {2009},
	publisher = {American Physical Society},
	abstract = {We study the effect of membrane viscosity in the dynamics of liquid membranes-possibly with free or internal boundaries-driven by conservative forces (curvature elasticity and line tension) and dragged by the bulk dissipation of the ambient fluid and the friction occurring when the amphiphilic molecules move relative to each other. To this end, we formulate a continuum model which includes a form of the governing equations for a two-dimensional viscous fluid moving on a curved, time-evolving surface. The effect of membrane viscosity has received very limited attention in previous continuum studies of the dynamics of fluid membranes, although recent coarse-grained discrete simulations suggest its importance. By applying our model to the study of vesiculation and membrane fusion in a simplified geometry, we conclude that membrane viscosity plays a dominant role in the relaxation dynamics of fluid membranes of sizes comparable to those found in eukaryotic cells, and is not negligible in many large synthetic systems of current interest.},
	doi = {10.1103/PhysRevE.79.031915},
	url = {http://hdl.handle.net/1963/3618},
	author = {Marino Arroyo and Antonio DeSimone}
}
@article {2008,
	title = {Relaxation of some transversally isotropic energies and applications to smectic A elastomers},
	journal = {Math. Models Methods Appl. Sci. 18 (2008) 1-20},
	number = {SISSA;01/2007/M},
	year = {2008},
	doi = {10.1142/S0218202508002693},
	url = {http://hdl.handle.net/1963/1912},
	author = {James Adams and Sergio Conti and Antonio DeSimone and Georg Dolzmann}
}
@inbook {2006,
	title = {Recent analytical developments in micromagnetics},
	booktitle = {The science of hysteresis / eds. Giorgio Bertotti, Isaak D. Mayergoyz. - Amsterdam: Elsevier, 2006. Vol.2, 269-381.},
	number = {SISSA;76/2004/M},
	year = {2006},
	isbn = {978-0-12-480874-4},
	url = {http://hdl.handle.net/1963/2230},
	author = {Antonio DeSimone and Robert V. Kohn and Stefan M{\"u}ller and Felix Otto}
}
