Untethered micro-robotic coding of three-dimensional material composition

Nat Commun. 2014;5:3124. doi: 10.1038/ncomms4124.


Complex functional materials with three-dimensional micro- or nano-scale dynamic compositional features are prevalent in nature. However, the generation of three-dimensional functional materials composed of both soft and rigid microstructures, each programmed by shape and composition, is still an unsolved challenge. Here we describe a method to code complex materials in three-dimensions with tunable structural, morphological and chemical features using an untethered magnetic micro-robot remotely controlled by magnetic fields. This strategy allows the micro-robot to be introduced to arbitrary microfluidic environments for remote two- and three-dimensional manipulation. We demonstrate the coding of soft hydrogels, rigid copper bars, polystyrene beads and silicon chiplets into three-dimensional heterogeneous structures. We also use coded microstructures for bottom-up tissue engineering by generating cell-encapsulating constructs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Biocompatible Materials / chemistry*
  • Cells, Immobilized / cytology
  • Chickens
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Hydrogels / chemistry
  • Mice
  • NIH 3T3 Cells
  • Robotics / methods*
  • Tissue Culture Techniques


  • Biocompatible Materials
  • Hydrogels