Microchannels with Self-Pumping Walls

2020

Article

pf

icm

When asymmetric Janus micromotors are immobilized on a surface, they act as chemically powered micropumps, turning chemical energy from the fluid into a bulk flow. However, such pumps have previously produced only localized recirculating flows, which cannot be used to pump fluid in one direction. Here, we demonstrate that an array of three-dimensional, photochemically active Au/TiO2 Janus pillars can pump water. Upon UV illumination, a water-splitting reaction rapidly creates a directional bulk flow above the active surface. By lining a 2D microchannel with such active surfaces, various flow profiles are created within the channels. Analytical and numerical models of a channel with active surfaces predict flow profiles that agree very well with the experimental results. The light-driven active surfaces provide a way to wirelessly pump fluids at small scales and could be used for real-time, localized flow control in complex microfluidic networks.

@article{2020Yu,
  title = {Microchannels with Self-Pumping Walls},
  author = {Yu, T. and Athanassiadis, A. G. and Popescu, M. N. and Chikkadi, V. and G{\"u}th, A. and Singh, D. P. and Qiu, T. and Fischer, P.},
  journal = {ACS Nano},
  volume = {14},
  number = {10},
  pages = {13673--13680},
  year = {2020},
  doi = {10.1021/acsnano.0c05826},
  url = {https://pubs.acs.org/doi/abs/10.1021/acsnano.0c05826}
}