A photonic device includes a silicon semiconductor based superlattice. The spacer is used as a reference for securing a guide jig in position about the knee joint for guiding resection of one or both of the femur and tibia for fitting of tibial andor femoral prostheses. The ratio of the flow rate of the fluorine-containing gas to the flow rate of the silicon-containing gas is greater than 0. The housing is coupled to the flexible display panel for enteringdischarging of the flexible display panel according to the first direction such that a display area of the flexible display panel is variously exposed. Genes under the control of promoters are protectively contained in microparticles and delivered to cells in operative form, thereby obtaining noninvasive gene delivery for gene therapy. Additionally, a wireless access point may be utilized for centralized communications between the transceivers and user workstations.