An electro-optic system is provided that includes a front element a rear element, and an electro-optic medium, the electro-optic medium is adapted to be in at least a high transmittance state and a low transmittance state. The cells of the invention are particularly, suited as bioreactors for carrying out enzymatic reaction cascades for which compartmentalization of individual enzymes is advantageous or necessary. In addition, the apparatus may include one or more clip segments detachably fastened to the main body portion of the frame segment.