The aliphatic spacer length connected to the rigid mesogenic cores is shown to control the structural organization and mechanical actuation in response to light-stimulus in azobenzene-functionalized liquid crystalline polymers networks. The spacer lengths in the mesogenic host (non-photochromic) and in the photo-active azobenzene-functionalized cross linker are parametrically varied to create monodomain liquid crystalline samples. A suite of thermomechanical, photomechanical and structural characterization is used to characterize the binary co-polymers. The photomechanical responses are compared by calculating a figure-of-merit - Photocompliance (Cp). This parameter, Cp, which characterizes the incremental strain generated in response to unit intensity of irradiation (W/cm(2)), is found to correlate strongly with the S-xray order parameter and the D-spacings. We show that compact (smaller D) and higher ordering of the mesogens that result in copolymers with longer flexible spacers manifest greater photomechanical activity. (C) 2017 Elsevier Ltd. All rights reserved.