In this research, we used a profoundly new approach to synthesize liquid-crystalline elastomers (LCEs) based on using a thiol-acrylate “click” reaction and two-stage thiol-acrylate Michael additionphotopolymerization (TAMAP) reaction, both of which have not previously been investigated for LCE synthesis. The thiol-acrylate reaction was used initially to synthesize polydomain LCEs and then to examine the influence of crosslinking and spacer length. First, the influence of crosslinking on the thermomechanical behavior of LCEs was investigated. The isotropic rubbery modulus, glass transition temperature, and strain-to-failure showed strong dependence on crosslinker amount and ranged from 0.9 MPa, 3°C, and 105% to 3.2 MPa, 25°C, and 853%, respectively. The isotropic transition temperature (Ti) was shown to be influenced by the functionality of the crosslinker, while the crosslinker concentration had no effect. The magnitude of actuation can be tailored by controlling the amount of crosslinker and applied stress. Actuation increased with increasing the applied stress and decreased with greater amounts of crosslinking. Second, we hypothesized that tuning the LC phases in main-chain LCE systems can be achieved by varying the spacer length while maintaining the same mesogen (RM257). By increasing the length of spacers from two to eleven carbons along the spacer backbone (C2 to C11), we can modulate the mesophase from nematic to smectic, tailor the nematic to isotropic transition temperature between 90 and 140°C, and increase the average work capacity from 128 to 262 kJ/m³ . Phase segregation and the smectic C phase is achieved at room temperature for the C6, C9, and C11 spacers. Upon heating, these samples transition into the nematic and later, the isotropic phase. Furthermore, this segregation occurs along with polymer chain crystallinity, which increasing the modulus of the networks by an order of magnitude; however, the crystallization rate is highly time dependent on the spacer length and can vary between 5 minutes for the C11 spacer and 24 hours for shorter spacers. A novel TAMAP methodology was implemented to synthesize monodomain LCEs using commercially available starting monomers. A wide range of thermomechanical properties was tailored by adjusting the amount of crosslinker, while the actuation performance was dependent on the amount of applied strain during programming.