A liquid-transfer device for use in transferring a liquid, the device comprising: - a lateral capillary flow matrix capable of producing a lateral capillary flow of said liquid via a capillary flow unipath from an upstream end to a downstream end of said capillary flow unipath; wherein the lateral capillary flow matrix has a pore size in the range of 1-15μm to produce a lateral capillary flow rate therein; a housing having a top wall including a liquid inlet, a bottom wall underlying said lateral capillary flow matrix, an upstream end wall at the upstream end of said capillary flow unipath adjacent to said liquid inlet, a downstream end wall at the downstream end of said capillary flow unipath, and an absorbent body located between said downstream end of the capillary flow unipath and said downstream end wall; a liquid-transfer matrix (26, 76) positioned in the housing in full planar contact with the lateral capillary flow matrix and having capillary passageways which are in fluid communication with the lateral capillary flow matrix; wherein the liquid-transfer matrix has a pore size in the range of 0.1μm - 5 μm to produce a lateral capillary flow rate therein which is lower than the lateral capillary fluid flow rate in the lateral capillary flow matrix which produces a lower pressure between the two lateral capillary flows whereby, in parallel to the lateral flow taking place in the lateral capillary flow matrix, there is an oscillatory transverse flow between the two matrices which drives the liquid into the interior of the liquid-transfer matrix thereby exposing the interior of the liquid-transfer matrix, rather than merely a surface thereof, to the liquid. a lateral capillary flow matrix capable of producing a lateral capillary flow of said liquid via a capillary flow unipath from an upstream end to a downstream end of said capillary flow unipath; wherein the lateral capillary flow matrix has a pore size in the range of 1-15μm to produce a lateral capillary flow rate therein; a housing having a top wall including a liquid inlet, a bottom wall underlying said lateral capillary flow matrix, an upstream end wall at the upstream end of said capillary flow unipath adjacent to said liquid inlet, a downstream end wall at the downstream end of said capillary flow unipath, and an absorbent body located between said downstream end of the capillary flow unipath and said downstream end wall; a liquid-transfer matrix (26, 76) positioned in the housing in full planar contact with the lateral capillary flow matrix and having capillary passageways which are in fluid communication with the lateral capillary flow matrix; wherein the liquid-transfer matrix has a pore size in the range of 0.1μm - 5 μm to produce a lateral capillary flow rate therein which is lower than the lateral capillary fluid flow rate in the lateral capillary flow matrix which produces a lower pressure between the two lateral capillary flows whereby, in parallel to the lateral flow taking place in the lateral capillary flow matrix, there is an oscillatory transverse flow between the two matrices which drives the liquid into the interior of the liquid-transfer matrix thereby exposing the interior of the liquid-transfer matrix, rather than merely a surface thereof, to the liquid.