A method for manufacturing a switchable PBD includes filling a plurality of first-type particles and a plurality of second-type particles into each cell, where the plurality of first-type particles carries charges of a first charge polarity having a first charge density and the plurality of second-type particles is substantially electrically neutral, or carries charges having a second charge density that is substantially lower than the first charge density of the first-type particles, and filling a fluid into each cell, where the fluid comprises a charge controlling agent having a second charge polarity opposite to the first charge polarity, and the charge controlling agent has a substantially selective wettability, absorbability or adsorbability on the plurality of second-type particles. As such, at least part of the plurality of second-type particles is charged to have the second charge polarity in each cell.