A 3-dimensional dielectrophoretic (DEP) sorting device , the device comprising: a first electrode layer ; a second electrode layer ; and an electrically-insulating layer interposed between the first electrode layer and the second electrode layer , wherein: the electrically-insulating layer includes a first sub-layer and a second sub-layer; a first passage is located in the first sub-layer, a second passage is located in the second sub-layer, the first electrode layer , the second electrode layer , and the electrically-insulating layer form a substantially planar assembly, the first electrode layer is on an opposite side of the first sub-layer from the second sub-layer, the second electrode layer is on an opposite side of the second sub-layer from the first sub-layer, the first passage and the second passage follow a common path within a DEP separation region of the electrically-insulating layer and are in direct fluid communication with one another within the DEP separation region, the first passage and the second passage each have a different cross-sectional width perpendicular to the common path and perpendicular to a normal of the substantially planar assembly, and the first passage diverges from the second passage in a post-DEP separation region, the post-DEP separation region located downstream of the DEP separation region . a first electrode layer ; a second electrode layer ; and an electrically-insulating layer interposed between the first electrode layer and the second electrode layer , wherein: the electrically-insulating layer includes a first sub-layer and a second sub-layer; a first passage is located in the first sub-layer, a second passage is located in the second sub-layer, the first electrode layer , the second electrode layer , and the electrically-insulating layer form a substantially planar assembly, the first electrode layer is on an opposite side of the first sub-layer from the second sub-layer, the second electrode layer is on an opposite side of the second sub-layer from the first sub-layer, the first passage and the second passage follow a common path within a DEP separation region of the electrically-insulating layer and are in direct fluid communication with one another within the DEP separation region, the first passage and the second passage each have a different cross-sectional width perpendicular to the common path and perpendicular to a normal of the substantially planar assembly, and the first passage diverges from the second passage in a post-DEP separation region, the post-DEP separation region located downstream of the DEP separation region . the electrically-insulating layer includes a first sub-layer and a second sub-layer; a first passage is located in the first sub-layer, a second passage is located in the second sub-layer, the first electrode layer , the second electrode layer , and the electrically-insulating layer form a substantially planar assembly, the first electrode layer is on an opposite side of the first sub-layer from the second sub-layer, the second electrode layer is on an opposite side of the second sub-layer from the first sub-layer, the first passage and the second passage follow a common path within a DEP separation region of the electrically-insulating layer and are in direct fluid communication with one another within the DEP separation region, the first passage and the second passage each have a different cross-sectional width perpendicular to the common path and perpendicular to a normal of the substantially planar assembly, and the first passage diverges from the second passage in a post-DEP separation region, the post-DEP separation region located downstream of the DEP separation region . <EOS>