Poly(ethylene glycol) micropillars with gold nanopatterns on top are functionalized with two integrin selective ligands. This platform is a powerful new tool to determine the specific contribution of traction forces involved in cell adhesion mediated by α5 β1‐ and αvβ3‐ integrins. Cells adherent via α5 β1‐integrins have a tendency to exert higher maximum forces than cells adhering via αvβ3‐integrins.

Complex systems require their distinct components to function in a dynamic, integrated, and cooperative fashion. To accomplish this in current microfluidic networks, individual valves are often switched and pumps separately powered by using macroscopic methods such as applied external pressure. Direct manipulation and control at the single-device level, however, limits scalability, restricts portability, and hinders the development of massively parallel architectures that would take best advantage of microscale systems. In this article, we demonstrate that local geometry combined with a simple global field can not only reversibly drive component assembly but also power distinct devices in a parallel, locally uncoupled, and integrated fashion. By employing this single approach, we assemble and demonstrate the operation of check valves, mixers, and pistons within specially designed microfluidic environments. In addition, we show that by linking these individual components together, more complex devices such as pumps can be both fabricated and powered in situ.colloids ͉ microfluidics ͉ micromachines

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