Smart Magnetic Colloids Perform Simple Robotic Functions
Film strip demonstrating capture of target particle (1 mm glass bead)
by self-assembled aster-robot.
Scientists from Argonne National Laboratory, IL, have given new meaning to the phrase "smart materials." The materials they have developed not only self-assemble from simple building blocks, they also perform elaborate mechanical functions such as grasping, transporting and releasing cargo as illustrated below and in this Argonne Press Room article.
The materials consist of a dispersion of magnetic microparticles confined at the interface between two immiscible liquids and energized by an alternating magnetic field. They self-assemble into miniature star-like structures – asters - that are remotely controlled by an alternating magnetic field to open and close around a target particle, swim, and then release the captured particle as a distant location.
The controllable mechanical function of these smart materials imitates the operation of much more complex biological and technological machines, yet is accomplished with remarkably simple and inexpensive constituents. The possibilities are endless, including self-repair, multi-tasking, and reconfiguring to perform any of several tasks. This new horizon of smart, functional materials in a new direction for materials science with exciting implications.
The research was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering, under Contract No. DE AC02-06CH11357.
- A. Snezhko and I.S. Aranson, Magnetic manipulation of self-assembled colloidal asters, Nature Materials, DOI 10.1038/nmat3083.