Fabrication of Asymmetric Tubular Hydrogels through Polymerization-Assisted Welding for Thermal Flow Actuated Artificial Muscles

Huijuan Lin, Shuanhong Ma, Bo Yu, Meirong Cai, Zijian Zheng, Feng Zhou, Weimin Liu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

17 Citations (Scopus)


By nature, diversified motions in most muscle systems are accompanied by fluid transportation. Inspired by the fluid-induced actuation behavior of Urechis unicinctus, we introduce a two-step fixed-site selective surface catalytically initiated radical polymerization strategy to prepare asymmetric thermoresponsive hydrogel tubes (as-TRTs) containing the responsive PNIPAAmx-PAAy part and nonresponsive PAMx-PAAy part with perfect interface fusion, including uniform structure (I), Janus structure (II), and block structure (III). In a typical case, we can easily obtain three kinds of multiple-channel as-TRTs with complex geometries by using multiple wires as a growth template and three kinds of TRTs with patterned, thread, and spiral structures. Meanwhile, the as-TRTs can achieve dynamic bending based on the generated interface stress difference from up to 7 times modulus value change for its thermoresponsive part upon immersing the tubes into a hot water bath or injecting the hot fluid into the channels. The prepared as-TRTs can bend or twist depending on their flexible geometric design. Devices made with these asymmetric hydrogel tubes can capture/release or lift objects both underwater and in air, convert thermal stimulation to the transportation capability of the fluid, gas or mix different kinds of liquids, and act as intelligent multichannel fluidic switchers. The current work is highly anticipated to open new frontiers for developing stimuli-responsive "smart" soft robots.

Original languageEnglish
Pages (from-to)4469-4478
Number of pages10
JournalChemistry of Materials
Issue number12
Publication statusPublished - 25 Jun 2019

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

Cite this