This paper describes a simple system for the actuation of a biological fluid through micro-channels with a thermoactivated polymer actuator. This system is of interest for the development of single-use diagnostic test-strips since the actuation of the sample is integrated in the disposable test strip. On chip actuation has the advantage of reducing the size and the cost of the non disposable part of the measurement system and preventing any contamination of the sample since it is completely isolated from any non- disposable elements. The study of the developed system was done optically by monitoring the fluid progression in the channel. It has demonstrated typical flow range of 10 to 60 nl/min. A similar device was then used to prove its application to blood coagulation characterization based on an increase in blood viscosity. Such a system can find diverse applications in chemical analysis and diagnostics on chip where actuation by steps from nano to microliter range is required.