@article {39,
	title = {Liquid crystal elastomer strips as soft crawlers},
	journal = {Journal of the Mechanics and Physics of Solids},
	volume = {84},
	year = {2015},
	pages = {254-272},
	abstract = {<p align="justify">In this paper, we speculate on a possible application of Liquid Crystal Elastomers to the field of soft robotics. In particular, we study a concept for limbless locomotion that is amenable to miniaturisation. For this purpose, we formulate and solve the evolution equations for a strip of nematic elastomer, subject to directional frictional interactions with a flat solid substrate, and cyclically actuated by a spatially uniform, time-periodic stimulus (e.g., temperature change). The presence of frictional forces that are sensitive to the direction of sliding transforms reciprocal, {\textquoteleft}breathing-like{\textquoteright} deformations into directed forward motion. We derive formulas quantifying this motion in the case of distributed friction, by solving a differential inclusion for the displacement field. The simpler case of concentrated frictional interactions at the two ends of the strip is also solved, in order to provide a benchmark to compare the continuously distributed case with a finite-dimensional benchmark. We also provide explicit formulas for the axial force along the crawler body.</p>},
	keywords = {crawling motility, directional surfaces, frictional interactions, liquid crystal elastomers, soft biomimetic robots},
	doi = {10.1016/j.jmps.2015.07.017},
	author = {Antonio DeSimone and Paolo Gidoni and Giovanni Noselli}
}
