A micro-fluidic chamber (1) for use in a liquid medicament delivery system has a bottom substrate (11) and a top cover (12), the top cover (12) being spaced from the bottom substrate (11) so as to define a height (H1) of the chamber (1). One or more walls or fillings (13) are positioned in the chamber (1), the walls or fillings (13) defining a fluid channel (2) there between such that the fluid channel (2) extends from an inlet (21) of the chamber to an outlet (22) of the chamber. Each of the walls or fillings (13) has a height (H2) less than the height (H1) of the chamber (1) so as to define a gap (3) between a top surface (131) of each wall or filling (13) and the top cover (12). The dimensions (H1, H2) of the walls or fillings (13) and the chamber (1) are chosen such that the fluid gap (3) will be filled with liquid (4) by capillary forces via the fluid channel (2) when liquid (4) is introduced into the fluid chamber (1).
