CC BY 4.0 UnportedPrieto-López, L.O.Xu, J.Cui, J.2020-01-142020-01-142019https://doi.org/10.34657/117https://oa.tib.eu/renate/handle/123456789/4846The handling of droplets in a controlled manner is essential to numerous technological and scientific applications. In this work, we present a new open-surface platform for droplet manipulation based on an array of bendable nozzles that are dynamically controlled by a magnetic field. The actuation of these nozzles is possible thanks to the magnetically responsive elastomeric composite which forms the tips of the nozzles; this is fabricated with Fe3O4 microparticles embedded in a polydimethylsiloxane matrix. The transport, mixing, and splitting of droplets can be controlled by bringing together and separating the tips of these nozzles under the action of a magnet. Additionally, the characteristic configuration for droplet mixing in this platform harnesses the kinetic energy from the feeding streams; this provided a remarkable reduction of 80% in the mixing time between drops of liquids about eight times more viscous than water, i.e., 6.5 mPa/s, when compared against the mixing between sessile drops of the same fluids. © 2019 by the authors.enghttps://creativecommons.org/licenses/by/4.0/620Droplet manipulationMagnetic responsive elastomersOpen-surface microfluidicsArticle