Abstract
The design of synthetic soft matter capable of emulating the complex behaviors of living organisms, such as sensing and adapting to their environment, remains an important challenge in developing biomimetic materials. Functionalized hydrogels are ideal candidates for such materials since they are highly responsive to their environment and can be operated in water. In this work, we investigate a hybrid bonding hydrogel composed of peptide amphiphile supramolecular nanofibers covalently attached to a photoresponsive network, in which high-aspect-ratio ferromagnetic nanowires are aligned along the length of the sample, designed to swim under oscillating magnetic fields. This hybrid hydrogel swimmer can autonomously swim toward a light source by utilizing photoinduced interactions between supramolecular and covalent networks reminiscent of phototactic swimming in living systems. Using a combination of experimental techniques and a continuum model incorporating photochemistry, magnetoelasticity, and hydrodynamics, we explain the swimming mechanism and predict phototactic behavior. Our work highlights the potential role of hybrid bonding polymers, which leverage the interplay between supramolecular assemblies and covalent networks. We demonstrate how these polymers can be tailored to react dynamically to their environment, paving the way for developing intelligent and autonomous robotic systems.
| Original language | English (US) |
|---|---|
| Article number | e2411092121 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 121 |
| Issue number | 50 |
| DOIs | |
| State | Published - Dec 10 2024 |
Funding
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 Office of Basic Energy Sciences, under award number DE-SC0000989. We are grateful to Mark Richard Karver, S. Biswas, Kasandra Chi Ching Lee, and Joe Grzybek of the Peptide Synthesis Core Facility of the Simpson Querrey Institute for BioNanotechnology at Northwestern University for their assistance and key insights into the synthesis and purification of the peptide amphiphiles. The Simpson Querrey Institute, Northwestern University Office for Research, also provided funding to develop this facility. This work also made use of the Electron Probe Instrumentation Center (EPIC) and Biological Cryo Electron Microscopy Facility (BioCryo) facilities, as well as Northwestern University's Atomic and Nanoscale Characterization Experimental (NUANCE) Center, which has received support from the Soft and Hybrid Nanotechnology Experimental Resource (NSF ECCS-1542205); the Materials Research Science and Engineering Center (MRSEC) Program (NSF DMR-1720139) at the Materials Research Center; the International Institute for Nanotechnology (IIN); and the State of Illinois, through the IIN and the MRI program (NSF DMR-1229693). This work also made use of the Materials Characterization and Imaging (MatCI) Facility, which receives support from the MRSEC Program (NSF DMR-1720139) of the Materials Research Center at Northwestern University. S.D.C. acknowledges support from Northwestern University and IIN through a Ryan Fellowship.
Keywords
- bio-inspired phototaxis
- continuum modeling
- hybrid hydrogels
- magnetic fields
- soft robots
ASJC Scopus subject areas
- General