Abstract
The design of soft matter in which internal fuels or an external energy input can generate locomotion and shape transformations observed in living organisms is a key challenge. Such materials could assist in productive functions that may range from robotics to smart management of chemical reactions and communication with cells. In this context, hydrated matter that can function in aqueous media would be of great interest. Here, we report the design of hydrogels containing a scaffold of high-aspect ratio ferromagnetic nanowires with nematic order dispersed in a polymer network that change shape in response to light and experience torques in rotating magnetic fields. The synergistic response enables fast walking motion of macroscopic objects in water on either flat or inclined surfaces and also guides delivery of cargo through rolling motion and light-driven shape changes. The theoretical description of the response to the external energy input allowed us to program specific trajectories of hydrogel objects that were verified experimentally.
Original language | English (US) |
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Article number | abb9822 |
Journal | Science Robotics |
Volume | 5 |
Issue number | 49 |
DOIs | |
State | Published - Dec 16 2020 |
Funding
We thank J. E. Kupferberg for preparation of the alginate beads and M. Seniw for schematic illustrations. This work made use of the IMSERC at Northwestern University, which has received support from the NIH (1S10OD012016-01/1S10RR019071-01A1), Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205), the State of Illinois, and the International Institute for Nanotechnology (IIN). This work also made use of the MatCI Facility, which receives support from the MRSEC Program (NSF DMR-1720139) of the Materials Research Center at Northwestern University. The x-ray scattering experiment was performed at the DuPont-Northwestern-Dow Collaborative Access Team (DND-CAT) located at Sector 5 of the Advanced Photon Source (APS). DND-CAT is supported by Northwestern University, Dow Chemical Company, and DuPont de Nemours Inc., and APS is a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract no. DE-AC02-06CH11357. Data were collected using an instrument funded by the NSF under award no. 0960140. This work was supported by the Center for Bio-Inspired Energy Science (CBES), an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences under award number DE-SC0000989.
ASJC Scopus subject areas
- General Medicine