Thumb ticker sm ting ting
Micro, Nano, and Molecular Systems
no image
Micro, Nano, and Molecular Systems
Thumb ticker sm vijay
Micro, Nano, and Molecular Systems
Thumb ticker sm dhruv2
Micro, Nano, and Molecular Systems
Thumb ticker sm qiu  tian
Micro, Nano, and Molecular Systems
Univ. of Stuttgart CyberValley Group Leader & MPI Senior Research Scientist
Thumb ticker sm peer fischer portrait
Micro, Nano, and Molecular Systems
Professor
Selfpumping microfluidics

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.

Author(s): Yu, T. and Athanassiadis, A. G. and Popescu, M. N. and Chikkadi, V. and Güth, A. and Singh, D. P. and Qiu, T. and Fischer, P.
Journal: ACS Nano
Volume: 14
Number (issue): 10
Pages: 13673--13680
Year: 2020
Bibtex Type: Article (article)
DOI: 10.1021/acsnano.0c05826
URL: https://pubs.acs.org/doi/abs/10.1021/acsnano.0c05826
Electronic Archiving: grant_archive

BibTex

@article{2020Yu,
  title = {Microchannels with Self-Pumping Walls},
  journal = {ACS Nano},
  abstract = {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.},
  volume = {14},
  number = {10},
  pages = {13673--13680},
  year = {2020},
  slug = {2020yu},
  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.},
  url = {https://pubs.acs.org/doi/abs/10.1021/acsnano.0c05826}
}