Photopatternable NdFeB polymer micromagnets for microfluidics and microrobotics applications

Microscale sensors and transducers based on magnetic forces can be used to provide wireless, contamination-free interaction with micro- and nanoenvironments. However, integration of magnetic components with typical microfabrication processes can be challenging. Here we show the creation and characterization of polymer micromagnets that can be utilized in microelectromechanical systems (MEMS), microfluidics, microassembly and microrobotics applications. These magnets can be patterned using standard UV lithography, are inexpensive to manufacture, and require limited equipment to produce. We demonstrate the creation of polymer micromagnets with 3 µm feature resolution and greater than 10:1 aspect ratio, the controlled movement of freestanding structures using contact-free applied magnetic fields, and the fabrication of novel ‘hybrid’ magnetic microstructures with controlled heterogeneity of magnetic properties.

[1]  Nicole Pamme,et al.  Magnetism and microfluidics. , 2006, Lab on a chip.

[2]  M.R.J. Gibbs,et al.  Magnetic materials for MEMS applications , 2004 .

[3]  P. Renaud,et al.  Conductive SU8 Photoresist for Microfabrication , 2005 .

[4]  N. Allbritton,et al.  Transparent magnetic photoresists for bioanalytical applications. , 2010, Biomaterials.

[5]  Kee Suk Ryu,et al.  A magnetic microstirrer and array for microfluidic mixing , 2002 .

[6]  Brian L. Wardle,et al.  Fabrication and Nanocompression Testing of Aligned Carbon‐Nanotube–Polymer Nanocomposites , 2007 .

[7]  Metin Sitti,et al.  An untethered magnetically actuated micro-robot capable of motion on arbitrary surfaces , 2008, 2008 IEEE International Conference on Robotics and Automation.

[8]  George M. Whitesides,et al.  Composite ferromagnetic photoresist for the fabrication of microelectromechanical systems , 2005 .

[9]  Lixin Dong,et al.  Artificial bacterial flagella: Fabrication and magnetic control , 2009 .

[10]  M. Despont,et al.  SU-8: a low-cost negative resist for MEMS , 1997 .

[11]  Ajit Khosla,et al.  Fabrication of UV-micro-patternable permanent micro magnets for lab on a chip and MEMS , 2010, Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[12]  N. Chronis,et al.  Electrothermally activated SU-8 microgripper for single cell manipulation in solution , 2005, Journal of Microelectromechanical Systems.

[13]  Howon Lee,et al.  Programming magnetic anisotropy in polymeric microactuators. , 2011, Nature materials.

[14]  David H Gracias,et al.  Tetherless thermobiochemically actuated microgrippers , 2009, Proceedings of the National Academy of Sciences.

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

[16]  Takayuki Fujita,et al.  Micro-structuring of thick NdFeB films using high-power plasma etching for magnetic MEMS application , 2011 .

[17]  C. Macosko,et al.  Spin coating: One‐dimensional model , 1989 .

[18]  David Brown,et al.  Developments in the processing and properties of NdFeb-type permanent magnets , 2002 .

[19]  Michael J. O'Brien,et al.  Rapid prototyping of active microfluidic components based on magnetically modified elastomeric materials , 2001 .

[20]  Ioannis K. Kaliakatsos,et al.  Microrobots for minimally invasive medicine. , 2010, Annual review of biomedical engineering.

[21]  Jörg Seyfried,et al.  Flexible microrobots for micro assembly tasks , 2000, MHS2000. Proceedings of 2000 International Symposium on Micromechatronics and Human Science (Cat. No.00TH8530).

[22]  Tingrui Pan,et al.  Photopatternable Superhydrophobic Nanocomposites for Microfabrication , 2010, Journal of Microelectromechanical Systems.

[23]  Babak Ziaie,et al.  A magnetically driven PDMS micropump with ball check-valves , 2005 .

[24]  George J. Pappas,et al.  Single Cell Manipulation using Ferromagnetic Composite Microtransporters , 2010 .

[25]  G. Reyne,et al.  Magnetic micro-actuators and systems (MAGMAS) , 2003 .

[26]  S. X. Wang,et al.  Magnetic, Mechanical, and Optical Characterization of a Magnetic Nanoparticle-Embedded Polymer for Microactuation , 2011, Journal of Microelectromechanical Systems.

[27]  Weisong Wang,et al.  Composite elastic magnet films with hard magnetic feature , 2004 .

[28]  Chang Liu,et al.  Micro magnetic silicone elastomer membrane actuator , 2001 .

[29]  William S. N. Trimmer,et al.  Microrobots and micromechanical systems , 1989 .

[30]  M. Gijs,et al.  A PMMA valveless micropump using electromagnetic actuation , 2005 .

[31]  M. Prins,et al.  Magnetization and actuation of polymeric microstructures with magnetic nanoparticles for application in microfluidics , 2009 .

[32]  J. W. Brown,et al.  Suspension of nanoparticles in SU-8: Processing and characterization of nanocomposite polymers , 2008, Microelectron. J..

[33]  Dominic R. Frutiger,et al.  Wireless resonant magnetic microactuator for untethered mobile microrobots , 2008 .

[34]  C. Hierold,et al.  A photopatternable superparamagnetic nanocomposite: Material characterization and fabrication of microstructures , 2011 .