Micro-fluidic Device comprising (a) microfluidics embedded in an optically transparent polymer supported film, the film comprising a 0.05-30 μm thin polymer top layer, and a 50-2000 μm polymer bottom layer in contact with the polymer top layer, and comprising at least one of a second micro-channel and one second micro-chamber at least partly embedded in the polymer bottom layer, (b) microfluidics embedded in a rigid substrate in micro-fluidic contact with the top layer of the polymer based microfluidics and the substrate supporting the polymer based microfluidics, wherein the substrate based microfluidics are accessible and/or can be made accessible for use of the device, and wherein the substrate is silicon or dielectric on silicon, comprising at least one of a first micro-channel and a first micro-chamber at least partly embedded in the substrate, wherein at least one of the first micro-channel and the first micro-chamber embedded in the substrate is accessible from the outside, wherein the polymer top layer 20a is for separating at least one of the first micro-channel 11 and/or at least one of the first micro-chamber 12 embedded in the substrate from at least one of the second micro-channel 21 and/or at least one of the second micro-chamber 22 embedded in the polymer bottom layer, and at least one input, the input being in microfluidic contact with the at least one of the second micro-channel and the second micro-chamber embedded in the polymer bottom layer, and the polymer top layer separating at least one of the first micro-channel and the first micro-chamber embedded in the substrate from at least one of the second micro-channel and the second micro-chamber embedded in the polymer bottom layer at least partly by a matrix of holes therein. (a) microfluidics embedded in an optically transparent polymer supported film, the film comprising a 0.05-30 μm thin polymer top layer, and a 50-2000 μm polymer bottom layer in contact with the polymer top layer, and comprising at least one of a second micro-channel and one second micro-chamber at least partly embedded in the polymer bottom layer, (b) microfluidics embedded in a rigid substrate in micro-fluidic contact with the top layer of the polymer based microfluidics and the substrate supporting the polymer based microfluidics, wherein the substrate based microfluidics are accessible and/or can be made accessible for use of the device, and wherein the substrate is silicon or dielectric on silicon, comprising at least one of a first micro-channel and a first micro-chamber at least partly embedded in the substrate, wherein at least one of the first micro-channel and the first micro-chamber embedded in the substrate is accessible from the outside, wherein the polymer top layer 20a is for separating at least one of the first micro-channel 11 and/or at least one of the first micro-chamber 12 embedded in the substrate from at least one of the second micro-channel 21 and/or at least one of the second micro-chamber 22 embedded in the polymer bottom layer, and at least one input, the input being in microfluidic contact with the at least one of the second micro-channel and the second micro-chamber embedded in the polymer bottom layer, and the polymer top layer separating at least one of the first micro-channel and the first micro-chamber embedded in the substrate from at least one of the second micro-channel and the second micro-chamber embedded in the polymer bottom layer at least partly by a matrix of holes therein.