@article {DESIMONE2015254,
	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>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},
	issn = {0022-5096},
	doi = {https://doi.org/10.1016/j.jmps.2015.07.017},
	url = {http://www.sciencedirect.com/science/article/pii/S0022509615300430},
	author = {Antonio DeSimone and Paolo Gidoni and Giovanni Noselli}
}
