Animal studies are commonly used to test the feasibility and effectiveness of promising novel neu- roscience research ideas. One such new technique is optogenetic stimulation, a state-of-the-art brain stimulation technique. In optogenetics, genetic techniques are used to create light-sensitive proteins within the neuron membrane, thus allowing the affected region to become sensitive to light stimulation, for example through an inserted LED. Current optogenetic stimulation methods use tethered setups and, typically, the animal-under-study is put into a fixed position. This introduces stress, which, besides an obvious reduction in animal welfare, may also influence the experimental results. Hence, an untethered setup is highly desirable. Therefore, in this study, we propose a wireless optogenetic stimulation setup, which allows for full freedom of movement of multiple rodents-under-study in a 40 cm x 40 x cm x 20 cm environment. We investigate a variety of wireless power transfer methods, which results in the choice for wireless power transfer through inductive coupling, as this allows for efficient power transfer over short range and has the least side-effects, making it the most suitable approach for this particular environment. The efficiency of inductive coupling is highly susceptible to vertical, lateral and angular misalignment of the coils. The wireless link is, therefore, designed to maximize the link efficiency and minimize the misalignments between the coils. In order to maximize the inductive power transfer link, we look into all the aspects that have an influence on the link efficiency, including coil shape and coil material. The implementation of the wireless optogenetics setup is divided into three parts: Transmitter Coil: The design of a transmitter coil capable of providing sufficient link efficiency through- out the entire 40 cm x 40 cm x 20 cm region of interest, in order to be able to power the optogenetic stimulation receiver, regardless of lateral and vertical misalignments. Receiver Module: The design of a receiver module that resides on the animal and, as such, is severely restricted in both size and weight. The complete module with receiver coil, rectifying and regulating electronics and microcontroller can occupy at most 1 cm x 1 cm x_ 1 cm and weights below 1 g. Moreover, half of allowable volume of the receiver module is kept unused for the future assembly including the wireless ECoG recording electronics. Optogenetics Optrodes: The creation of optogenetics optrodes using a novel µLED mounting tech- nique, which allows for the µLED array with multiple LEDs to be directly inserted into the brain. The use of a µLED array greatly improves the power efficiency, as the traditional LED-to-optical- fiber coupling is accompanied by large losses in light-intensity. Moreover, a single optrode is able to replace a number of optical fibers, resulting in a less-invasive procedure if multiple stimulation sites are required. For an input current of 0.5 A into the primary coil, an average inductive link efficiency of 0.28 %, and an angular misalignment of 45 degrees, the _nal setup is capable of delivering at least 8.5 mW of light power into the brain.