A microfluidic device comprising: a first network of channels having a plurality of First Channels, each First Channel having a height in the range of 50 microns to 500 microns and a width in the range of 50 microns to 1.5 millimeters; a second network of channels having at least one Second Channel complementary to one or more of the First Channels; a filtration membrane separating the one or more First Channels from the at least one Second Channel; wherein the plurality of First Channels further comprises: an input channel forming a primary channel, a plurality of secondary channels (604A, 604B), and an outlet channel, wherein the primary channel bifurcates into first and second secondary channels (604A, 604B) at a first junction, such that a volumetric fluid flow rate through the first secondary channel is the same as a volumetric fluid flow rate through the second secondary channel, and the total volumetric fluid flow rate between the first and second secondary channels is the same as the volumetric fluid flow rate through the primary channel; a first tertiary channel connecting to the first secondary channel at a second junction located at a first distance from the first junction; and a second tertiary channel connecting to the first secondary channel at a third junction located at a second distance, greater than the first distance, from the first junction, wherein the first secondary channel and the first and second tertiary channels are configured such that volumetric flow of fluid through the first secondary channel beyond the second junction is greater than volumetric flow of fluid into the first tertiary channel; wherein at least one of the first and second tertiary channels bifurcates into first and second quaternary channels at a fourth junction, such that a volumetric fluid flow rate through the first quaternary channel is the same as a volumetric fluid flow rate through the second quaternary channel, and the total volumetric fluid flow rate through the first and second quaternary channels is the same as the volumetric fluid flow rate through the portion of the at least one tertiary channel between the first secondary channel and the fourth junction, the microfluidic device further comprising a flow divider for dividing fluid flow between the first and second quaternary channels (608A, 608B), wherein the flow divider has a curved surface connecting to the walls of the first and second quaternary channels (608A; 608B), and the radius of curvature of the flow divider is not greater than the hydraulic diameter of the at least one tertiary channel. a first network of channels having a plurality of First Channels, each First Channel having a height in the range of 50 microns to 500 microns and a width in the range of 50 microns to 1.5 millimeters; a second network of channels having at least one Second Channel complementary to one or more of the First Channels; a filtration membrane separating the one or more First Channels from the at least one Second Channel; wherein the plurality of First Channels further comprises: an input channel forming a primary channel, a plurality of secondary channels (604A, 604B), and an outlet channel, wherein the primary channel bifurcates into first and second secondary channels (604A, 604B) at a first junction, such that a volumetric fluid flow rate through the first secondary channel is the same as a volumetric fluid flow rate through the second secondary channel, and the total volumetric fluid flow rate between the first and second secondary channels is the same as the volumetric fluid flow rate through the primary channel; a first tertiary channel connecting to the first secondary channel at a second junction located at a first distance from the first junction; and a second tertiary channel connecting to the first secondary channel at a third junction located at a second distance, greater than the first distance, from the first junction, wherein the first secondary channel and the first and second tertiary channels are configured such that volumetric flow of fluid through the first secondary channel beyond the second junction is greater than volumetric flow of fluid into the first tertiary channel; wherein at least one of the first and second tertiary channels bifurcates into first and second quaternary channels at a fourth junction, such that a volumetric fluid flow rate through the first quaternary channel is the same as a volumetric fluid flow rate through the second quaternary channel, and the total volumetric fluid flow rate through the first and second quaternary channels is the same as the volumetric fluid flow rate through the portion of the at least one tertiary channel between the first secondary channel and the fourth junction, the microfluidic device further comprising a flow divider for dividing fluid flow between the first and second quaternary channels (608A, 608B), wherein the flow divider has a curved surface connecting to the walls of the first and second quaternary channels (608A; 608B), and the radius of curvature of the flow divider is not greater than the hydraulic diameter of the at least one tertiary channel.