There is a great demand for smart partitions to serve as wide area switchable gates for light transaction across defined spaces at offices, public locations as well as homes. Partitions or windows that are in use presently are simply transparent at best and the desired degree of see-through visibility is achieved with permanent fixtures such as screens, curtains or such combinations. A new class of device has been fabricated in the laboratory with a toggle option between opaque (T~5%) and transparent states (T~ 85%) in select areas. The device consists of microfluidic cavities filled with a liquid optically matched with the glass substrate, thus rendering specular light transmission through the cavity. When devoid of the liquid, the cavities become translucent due to light scattering from the roughened internal wall surfaces. The present invention not only excels in achieving a uniformly specular state with no clue of the internal cavities but also produces reproducibly, an opaque state with no trace whatsoever of the wetting liquid that filled the cavity. Importantly, the device consumes no energy while being in any of the two states, and the only nominal consumption, if not operated manually, is during switching the states. It is envisaged that this new class of device will have a broad range of applications in automobile and modern infrastructure development industry due to its easily adaptable fabrication process and low cost.
