The present disclosure provides advantageous optical conduit assemblies (e.g., biocompatible and implantable optical conduit assemblies), and related methods of use. More particularly, the present disclosure provides advantageous optical conduit assemblies (e.g., polydimethylsiloxane (“PDMS”)-based optical conduit assemblies) configured to power implantable devices (e.g., neural micro-stimulators or deep brain stimulators or the like) or to be used in optogenetic stimulation. In general, the exemplary optical conduit assemblies can be used for applications where energy needs to be transmitted to deep locations inside the body or brain without using electrical wires. Therefore, implantable devices that need to be powered (e.g., neural prosthetics) can be powered from an external light source using an optical conduit and an optical-to-electrical converter (e.g., a photodiode) attached to the end of the optical conduit on the inside.