Figure 4: Morphing behaviour of PDLCEs with uniform LCE microparticle alignment.
(a) Illustration of thermal actuation of PDLCE disks, their axes of symmetry denoted by Z, with nematic directors n oriented ‘out-of-plane’ (top) and ‘in-plane’ (bottom), that is, with n||Z and n⊥Z. On heating to T>Tλ (blue-to-red arrow, also for c), the LCE material becomes isotropic (change of the nematic order parameter S from 1 (large orange double arrow) to 0 (vanishing orange double arrow) accompanied by contraction of μLCE particles along the nematic director n). The temperature of PDMS matrix is colour-coded in accordance with the colour bar of Fig. 1 (blue-cold, red-hot). Note that S=1 corresponds to ideal nematic order, never found in a real system. Deuteron NMR, performed on LCE-A with benzene-ring-labelled M4, yields S≈0.65 at Troom (ref. 51). (b) Macroscopically observed effective thermomechanical response of PDLCE composite: oblate deformation of the n||Z disk (top) and prolate deformation of the n⊥Z disk (bottom). (c) Top- and side-view photographs of n||Z (top) and n⊥Z (bottom) PDLCE-A disks at T=300 K<Tλ and T=400 K>Tλ, proving the concept of programmable PDLCE shape memory.
