fig7

Figure 7. Actuation of LCEs by other stimuli. (A) Organic solvent stimulated actuation. The schematic illustration on the left shows the two-step chemical reaction of the urease with LCEs. The optical images on the right show the urease-stimulated deformation of LCE stripes, including bending and helix. Reproduced with permission^[25]. Copyright 2021, American Chemical Society; (B) metal ion (Fe+) stimulated actuation. The schematic illustration shows that the mesogens/Bip changes from mesogenic phase to nonmesogenic phase upon binding the metal ion (Fe+). The photograph on the bottom shows that the LCE sample undergoes a macroscopic contraction after the actuation. Reproduced with permission^[130]. Copyright 2021, American Chemical Society; (C) swelling-induced actuation. The left photograph shows an isotropic shape actuation triggered by immersing in the solvent vapor. The right figure shows a time-dependent twist during the swelling-induced actuation. Reproduced with permission^[132]. Copyright 2017, Elsevier; (D) magnetothermal actuation. The schematic illustration shows the basic deformation mode and the controlling strategy for the LCEs responsive to the magnetic field. Reproduced with permission^[43]; (E) deformation of a LCE stripe under the combined thermal and swelling actuation. Scale bar, 5 mm. Reproduced with permission. Copyright 2017, The Royal Society of Chemistry; (F) deformation of a LCE-based composite under the combined photothermal and magnetic actuation. Reproduced with permission^[135]. Copyright 2021, Wiley-VCH GmbH; (G) a ferromagnetic LCE actuated by combined temperature and magnetic fields. The photograph shows a multi-function robot constructed by the ferromagnetic LCE. The robot can jump, roll, crawl, and carry loads. Scale bars, 5 mm. Reproduced with permission^[44]. Copyright 2021, Wiley-VCH.