title: A theoretical description of elastic pillar substrates in biophysical experiments.
abstract: Arrays of elastic pillars are used in biophysical experiments as sensors for traction forces. The evaluation of the forces can be complicated if they are coupled to the pillar displacements over large distances. This is the case if many of the pillars are interconnected by elastic linkages as, for example, in fiber networks that are grown on top of pillars. To calculate the traction forces in such a network, we developed a set of nonlinear inhomogeneous equations relating the forces in the linking elements to the resulting pillar deflections. We chose a homogeneous, activated two-dimensional network of cytoskeletal actin filaments to illustrate that a pillar substrate is generally not a force sensor but a force-gradient sensor. In homogeneous networks the forces acting along the filaments can be approximated by analyzing only pillar deflections in the edge zones of the substrate and by integration over the corresponding force gradients.
authors.affiliation: Universität Stuttgart, Institut für Metallkunde, Heisenbergstr. 3, 70569 Stuttgart, Germany.
authors.forename: Camilla
authors.initials: C
authors.lastname: Mohrdieck
authors.forename: Alexander
authors.initials: A
authors.lastname: Wanner
authors.forename: Wouter
authors.initials: W
authors.lastname: Roos
authors.forename: Alexander
authors.initials: A
authors.lastname: Roth
authors.forename: Erich
authors.initials: E
authors.lastname: Sackmann
authors.forename: Joachim P
authors.initials: JP
authors.lastname: Spatz
authors.forename: Eduard
authors.initials: E
authors.lastname: Arzt
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry*; D000465:Algorithms; D055592:Biophysical Phenomena; D001703:Biophysics; D008962:Models, Theoretical; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D012825:Silicon