Material assembly from collective action of shape-changing polymers

Mustafa K Abdelrahman; Robert J Wagner; Manivannan Sivaperuman Kalairaj; Mason Zadan; Min Hee Kim; Lindy K Jang; Suitu Wang; Mahjabeen Javed; Asaf Dana; Kanwar Abhay Singh; Sarah E Hargett; Akhilesh K Gaharwar; Carmel Majidi; Franck J Vernerey; Taylor H Ware

doi:10.1038/s41563-023-01761-4

Material assembly from collective action of shape-changing polymers

Nat Mater. 2024 Feb;23(2):281-289. doi: 10.1038/s41563-023-01761-4. Epub 2024 Jan 4.

Authors

Mustafa K Abdelrahman¹, Robert J Wagner^{2

3}, Manivannan Sivaperuman Kalairaj⁴, Mason Zadan⁵, Min Hee Kim⁴, Lindy K Jang^{4

6}, Suitu Wang¹, Mahjabeen Javed⁴, Asaf Dana⁴, Kanwar Abhay Singh⁴, Sarah E Hargett⁴, Akhilesh K Gaharwar⁴, Carmel Majidi⁵, Franck J Vernerey², Taylor H Ware^{7

8}

Affiliations

¹ Department of Materials Science and Engineering, Texas A&M University, College Station, TX, USA.
² Mechanical Engineering Department, Materials Science and Engineering Program, University of Colorado, Boulder, CO, USA.
³ Department of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA.
⁴ Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA.
⁵ Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA.
⁶ Materials Engineering Division, Lawrence Livermore National Laboratory, Livermore, CA, USA.
⁷ Department of Materials Science and Engineering, Texas A&M University, College Station, TX, USA. Taylor.Ware@tamu.edu.
⁸ Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA. Taylor.Ware@tamu.edu.

PMID: 38177377
DOI: 10.1038/s41563-023-01761-4

Abstract

Some animals form transient, responsive and solid-like ensembles through dynamic structural interactions. These ensembles demonstrate emergent responses such as spontaneous self-assembly, which are difficult to achieve in synthetic soft matter. Here we use shape-morphing units comprising responsive polymers to create solids that self-assemble, modulate their volume and disassemble on demand. The ensemble is composed of a responsive hydrogel, liquid crystal elastomer or semicrystalline polymer ribbons that reversibly bend or twist. The dispersions of these ribbons mechanically interlock, inducing reversible aggregation. The aggregated liquid crystal elastomer ribbons have a 12-fold increase in the yield stress compared with cooled dispersion and contract by 34% on heating. Ribbon type, concentration and shape dictate the aggregation and govern the global mechanical properties of the solid that forms. Coating liquid crystal elastomer ribbons with a liquid metal begets photoresponsive and electrically conductive aggregates, whereas seeding cells on hydrogel ribbons enables self-assembling three-dimensional scaffolds, providing a versatile platform for the design of dynamic materials.