A device and method for measuring the clotting times in a fluid, typically blood, within a microchannel whereby the onset of clotting is determined by measurement of the rate of change or value of capacitance or impedance between two electrodes situated on either side of the microchannel. There is provided a disposable test-strip (100) comprising an upper and lower support (101) and (103). A microchannel (102) is formed into the upper surface of the lower support member (103). A second substrate layer (101) is laminated on top of the support member (103), thereby closing the open microchannel (102). Electrodes (104) are formed on the respective outer surfaces of the substrate layers and coplanar to the channel.
