A microfluidic system may include an image sensor integrated circuit containing image sensor pixels. A channel containing a fluid with particles such as cells may be formed on top of the image sensor. Flow control components may be mounted to the image sensor integrated circuit for controlling the flow of fluids through the channel. The flow control components may include a chemically powered pump. The chemical pump may include one or more chambers and a valve between the chambers. The valve may be operable to allow chemical reactants stored in the chambers to be mixed to produce gasses for generating pressure in the channel. The pressure in the channel may be used to control the flow of the fluid. As the fluid and particles flow through the channel, the image sensor pixels may be used to capture images of the particles.