Achieving complex shape change of liquid-crystal polymer networks (LCNs) under stimulation generally requires spatial configuration of the orientation direction, that is, patterned directors, of liquid crystal monomers prior to polymerization by means of treated surfaces. A strategy is demonstrated that needs only the simple uniaxial orientation of mesogens (monodomain) induced by mechanical stretching of LCNs. Using a rationally designed liquid crystal polymer, photocrosslinking is utilized to pattern or spatially organize the actuating monodomains in order to generate a differential contractile and/or extensional force field required for targeted shape change. Moreover, the approach enables versatile actuation modes and allows multiple shape changes to be programmed on a single piece of the polymer. This important feature is demonstrated with a specimen cut to have eight strips that, upon thermal stimulation, simultaneously display eight types of shape morphing.

A strip of a liquid crystal elastomer doped with a near-infrared dye with one side crosslinked monodomain and the other crosslinked polydomain along the thickness behaves like a multifunctional photoactuator without the need for a support. A flat strip with two ends fixed on substrate surface forms a moving bump under laser scanning, which can be used as light-fueled conveyor to transport an object. Cutting off and laser scanning the bump with two free ends makes a soft and flexible millimeter-scale crawler that can not only move straight and climb an inclined surface, but also undergo light-guided turning to right or left as a result of combined out-of-plane and in-plane actuation. Based on the self-shadowing mechanism, with one end of the strip fixed on substrate surface, it can execute a variety of autonomous arm-like movements under constant laser illumination, such as bending-unbending and twisting, depending on the laser incident angles with respect to the strip actuator.

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A series of main-chain thermotropic liquid crystalline polyesters were synthesized by polycondensation from mesogenic dial as 4,4'-bis(6-hydroxyhexyloxy)biphenyl (BHHBP) and various diacids with different substituents as succinic acid (no side group), 2-methylsuccinic acid (aliphatic side group) and 2phenylsuccinic acid (aromatic side group), named as poly(4,4'-bis(6-hydroxyhexyloxy)biphenyl succinate) (PBDS), poly(4,4'-bis(6-hydroxyhexyloxy)biphenyl methylsuccinate) (PBDMS), poly(4,4'-10 bis(6-hydroxyhexyloxy)biphenyl phenylsuccinate) (PBDPS), respectively. Liquid crystalline behaviours were investigated through differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and small angle scattering (SAXS) and thermal stability of the polyesters was determined via thermogravimetric analysis (TGA). PBDS, PBDMS and PBDPS showed a SmF, SmB and SmA phase, respectively. With enlarging the side group, the d-spacing of the smectic layer increased, indicating a 15 folding packing of the polymer chains. Therefore, the adjacent phenyl rings in side groups stacked well together and formed strong π-π interaction even when the temperature was higher than T i .The special structure of PBDPS could endow the good mechanical property. Thus, PBDPS had the maximum tensile stress (28.6 MPa) and the highest elongation at break (1060 %). Furthermore, the strong π-π interaction can act as netpoints, therefore, PBDPS exhibited excellent shape fixing (>99 %) and shape recovery ratio 20 (>99 %) with large strain (>220 %). 65 question may be put forward: can these π-π interactions be strong enough to act as netpoints in a shape memory liquid crystalline polymer? If the answer is positive, the structural design of TLCP is very important.

The influence of the main-chain liquid crystalline polyester (PBDPS) on the crystallization and melting behaviors of isotactic polypropylene (iPP) has been investigated by differential scanning calorimetry (DSC), X-ray diffraction (WAXD), and polarized optical microscopy (POM). The results suggested that PBDPS is an efficient β-nucleating agent for iPP. The melting crystallization temperature as well as β-crystal of iPP increased with increasing of PBDPS content. The relative content of β-iPP crystals (k β) can reach 96.6% while adding 4% PBDPS during isothermal crystallization at 135 °C. The increased β-nucleation efficiency was ascribed to the adjacent phenyl rings in side groups of PBDPS stacked well together even when the temperature was higher than its clearing point (T i). Moreover, the distance between stacked phenyls is 0.32 nm, which is half of the unit cell parameter in the c-direction of β-iPP, indicating a lattice match between β-iPP and PBDPS.