May 27 2020
Artificial cilia, or hair-like structures, developed by researchers from North Carolina State University and Elon University have the ability to bend into novel shapes when subjected to a magnetic field. The cilia return to their original shape upon exposure to a proper light source.
Photograph of an array of magnetic cilia, folded and held in the tip of tweezers. Image Credit: Jessica A.-C. Liu.
This work expands the capabilities of magnetic cilia and our understanding of their behaviors, which has potential applications in soft robotics, including microrobotics. A key point of this work is that we’ve demonstrated shape memory magnetic cilia whose shape can be set, locked, unlocked and reconfigured. This property will be useful for enhanced and new applications.
Joe Tracy, Study Corresponding Author and Professor of Materials Science and Engineering, North Carolina State University
The study outcomes are based on a previous study by the team, in which soft robots that could be manipulated using light and magnets were developed. But there have been considerable deviations from the earlier study.
The cilia are actuated by magnetic torques, which means the cilia rotate and align with the field from an inexpensive permanent magnet, instead of being pulled toward the magnet. Actuation of the soft robots in our earlier work relied on magnetic field gradients, which moved the robot by pulling it. The new approach offers another tool for designing soft robots.
Ben Evans, Study Co-Author and Professor of Physics, Elon University
Furthermore, the researchers created a theoretical model to predict the response of the shape memory magnetic cilia to actuation, or upon being set into motion. The model also offers an explanation of why the cilia respond in a specific way.
These shape memory magnetic cilia are also simple to fabricate through self-assembly using inexpensive permanent magnets. We’re optimistic that these demonstrations and our model can help the research community design ciliary systems with new capabilities for specific applications.
Jessica Liu, Study First Author, North Carolina State University
Liu is a recent PhD graduate from NC State.
Tracy added, “We think this work will contribute to advancing the capabilities of soft robotics.”
The paper titled “Photothermally Reconfigurable Shape Memory Magnetic Cilia” was recently published in the Advanced Materials Technologies journal. The study was performed with financial support from the National Science Foundation (NSF) under grants CMMI-1663416 and CMMI-1662641.
The study was conducted, partially, at the Analytical Instrumentation Facility at NC State and the Duke University Shared Materials Instrumentation Facility, which are supported by the State of North Carolina and NSF grant ECCS-1542015.
Journal Reference:
Liu, J. A.‐C., et al. (2020) Photothermally Reconfigurable Shape Memory Magnetic Cilia. Advanced Materials Technologies. doi.org/10.1002/admt.202000147.