## 1 Introduction  
Liquid crystalline elastomers (LCEs) are a new unique class of material derived from the combination of elasticity properties (like in an elastomer) and orientational order of mesogenic building blocks (liquid crystalline molecular array). Typically, mesogenic units are incorporated as flexible spacers to build linear polymer liquid crystal macromolecules [1; 2; 3]. Since the monodomain alignment of mesogenic groups was thermodynamically unstable, due to its spontaneous conversion into polydomain structures, researchers were only synthesizing polydomain side-chain LCEs until the pioneering research works of [PERSON] and [PERSON] [4; 5]. They introduced new two-step crosslinking conditions to develop monodomain LCEs, where initially a weak crosslinked network was constructed; later, this developed director orientation was replicated by the second crosslinking step via mechanical stretching to induce monodomain [6; 7]. Evidently, for LCEs due to the coupling behavior of liquid crystalline order and the polymer backbone, external mechanical stress can considerably influence the state of an order [8; 9]. The crosslinking process in different liquid crystalline phases (nematic or isotropic phase) highly influences the oriental distribution and results in different properties [10]. When the crosslinking was done in the nematic phase, the state of order was fixed within the crosslinking zones, leading to 'frozen-in' order. This can be achieved by exposing the sample to the applied mechanical stress perpendicular to the original direction of the monodomain [11; 12; 13]. The synthetic strategy proposed by [PERSON] and [PERSON] for the preparation of monodomain nematic LCEs was sketched in Figure 1 with chemical structures used. Over the last two decades, the booming progress in designing different types of LCEs with a variety of liquid crystalline phase has been noticed for the fine-tuning of the properties. Researchers investigated a wide variety of LCEs with diverse liquid crystalline phases including nematic, cholesteric (or helical), smectic phases (smectic A, smectic C, and smectic C *), and discotic and blue phases [14; 15; 16; 17]. These LCEs with diversified liquid crystalline phases have been recognized as potentially effective to more technologically-related topics, such as adaptive varifocal micro lenses in miniature electronic devices to soft actuator components of artificial muscle along with biomedical and soft robotic applications [18; 19; 20; 21; 22]. Some of the prominently studied polymers are outlined in Figure 2. The structure presented in Figure 2a comprise polyimides with azobenzene chromophores in the main chain and it was initially reported by [PERSON] et al. [23]. Upon exposure to UV light, at the air/water interface, the stress diminution signpost the contraction of the monolayer. Under the dark condition, the stress increases again resulting in slight expansion of the monolayer. The photomechanical effects are caused by _trans-cis_ photoisomerization of azobenzene chromophores (are more linear in their _trans_ form than _cis_ form) that can occupy a large surface area at the interface [23]. The polypeptide monolayers comprising two \(\alpha\)-helical poly(\(\gamma\)-methyl L-glutamate) structures connected to azobenzene group prepared by [PERSON] et al. [24] demonstrate the geometrical structural discrepancy during _trans-cis_ photoisomerization resulting in the bending of the main chain (See Figure 2b). [PERSON] et al. [25] further investigated these photoresponsive behavior associated with polypeptides. The authors modified the structure (See Figure 2c) and introduced alky spacers. These monolayers demonstrated an expansion in UV light and contraction to the visible light. Upon exposure to UV light, the _trans-cis_ photoisomerization created a huge increase in the dipole moment resulting in high affinity to the water surface [25]. The similar properties were observed by poly(vinyl alcohol)s enclosing azobenzene side chains (for structure, see Figure 2d) developed by [PERSON] et al.