Three-dimensional heterogeneous assembly of coded microgels using an untethered mobile microgripper.

Three-dimensional (3D) heterogeneous assembly of coded microgels in enclosed aquatic environments is demonstrated using a remotely actuated and controlled magnetic microgripper by a customized electromagnetic coil system. The microgripper uses different 'stick-slip' and 'rolling' locomotion in 2D and also levitation in 3D by magnetic gradient-based pulling force. This enables the microrobot to precisely manipulate each microgel by controlling its position and orientation in all x-y-z directions. Our microrobotic assembly method broke the barrier of limitation on the number of assembled microgel layers, because it enabled precise 3D levitation of the microgripper. We used the gripper to assemble microgels that had been coded with different colours and shapes onto prefabricated polymeric microposts. This eliminates the need for extra secondary cross-linking to fix the final construct. We demonstrated assembly of microgels on a single micropost up to ten layers. By increasing the number and changing the distribution of the posts, complex heterogeneous microsystems were possible to construct in 3D.

[1]  Feng Xu,et al.  Three‐Dimensional Magnetic Assembly of Microscale Hydrogels , 2011, Advanced materials.

[2]  Metin Sitti,et al.  Two-Dimensional Autonomous Microparticle Manipulation Strategies for Magnetic Microrobots in Fluidic Environments , 2012, IEEE Transactions on Robotics.

[3]  Metin Sitti,et al.  Control of Multiple Heterogeneous Magnetic Microrobots in Two Dimensions on Nonspecialized Surfaces , 2012, IEEE Transactions on Robotics.

[4]  Metin Sitti,et al.  Assembly and disassembly of magnetic mobile micro-robots towards deterministic 2-D reconfigurable micro-systems , 2011, 2011 IEEE International Conference on Robotics and Automation.

[5]  M. Sitti,et al.  Three‐Dimensional Programmable Assembly by Untethered Magnetic Robotic Micro‐Grippers , 2014 .

[6]  D. Seliktar Designing Cell-Compatible Hydrogels for Biomedical Applications , 2012, Science.

[7]  Sunghoon Kwon,et al.  Three-dimensional fluidic self-assembly by axis translation of two-dimensionally fabricated microcomponents in railed microfluidics. , 2011, Small.

[8]  Metin Sitti,et al.  Control methodologies for a heterogeneous group of untethered magnetic micro-robots , 2011, Int. J. Robotics Res..

[9]  M. Sitti,et al.  Multiple magnetic microrobot control using electrostatic anchoring , 2009 .

[10]  A. Khademhosseini,et al.  Directed assembly of cell-laden microgels for fabrication of 3D tissue constructs , 2008, Proceedings of the National Academy of Sciences.

[11]  Ali Khademhosseini,et al.  Fabrication of three-dimensional porous cell-laden hydrogel for tissue engineering , 2010, Biofabrication.

[12]  Li Zhang,et al.  Fabrication and Characterization of Magnetic Microrobots for Three-Dimensional Cell Culture and Targeted Transportation , 2013, Advanced materials.

[13]  Metin Sitti,et al.  Modeling and Experimental Characterization of an Untethered Magnetic Micro-Robot , 2009, Int. J. Robotics Res..

[14]  Metin Sitti,et al.  Remotely addressable magnetic composite micropumps , 2012 .

[15]  Metin Sitti,et al.  Micro-manipulation using rotational fluid flows induced by remote magnetic micro-manipulators , 2012 .

[16]  M. Eremets,et al.  Ammonia as a case study for the spontaneous ionization of a simple hydrogen-bonded compound , 2014, Nature Communications.

[17]  Yuhui Li,et al.  Techniques for fabrication and construction of three-dimensional scaffolds for tissue engineering , 2013, International journal of nanomedicine.

[18]  Metin Sitti,et al.  Magnetic steering control of multi-cellular bio-hybrid microswimmers. , 2014, Lab on a chip.

[19]  José Antonio Cruz-Ledesma,et al.  Modelling, Design and Robust Control of a Remotely Operated Underwater Vehicle , 2014 .

[20]  Metin Sitti,et al.  Independent control of multiple magnetic microrobots in three dimensions , 2013, Int. J. Robotics Res..

[21]  Metin Sitti,et al.  Continuously distributed magnetization profile for millimeter-scale elastomeric undulatory swimming , 2014 .

[22]  Toshio Fukuda,et al.  On-chip self-assembly of cell embedded microstructures to vascular-like microtubes. , 2014, Lab on a chip.

[23]  Metin Sitti,et al.  Two-dimensional magnetic micro-module reconfigurations based on inter-modular interactions , 2013, Int. J. Robotics Res..

[24]  G. G. Stokes "J." , 1890, The New Yale Book of Quotations.

[25]  M. Sitti,et al.  Modular micro-robotic assembly through magnetic actuation and thermal bonding , 2013 .

[26]  Feng Xu,et al.  The assembly of cell-encapsulating microscale hydrogels using acoustic waves. , 2011, Biomaterials.

[27]  Ali Khademhosseini,et al.  Sequential assembly of cell‐laden hydrogel constructs to engineer vascular‐like microchannels , 2011, Biotechnology and bioengineering.

[28]  Feng Xu,et al.  Directed self-assembly of microscale hydrogels by electrostatic interaction , 2013, Biofabrication.

[29]  Ali Khademhosseini,et al.  Surface‐directed assembly of cell‐laden microgels , 2010, Biotechnology and Bioengineering.