The invention relates to a fluid flow device (1), comprising a system chip (11) having a substrate (12), a flow channel (21) defined within said substrate, and a sensor unit (41) connected to said flow channel for determining a property of a fluid in said flow channel. Furthermore, a valve unit (30) is provided within said substrate, for regulating fluid flow through said flow channel. The valve unit comprises a valve chamber (31) defined within said substrate, and a valve member (32) that is movably arranged within the valve chamber. The flow channel has a connection channel part (22) defined within said substrate (12), wherein said connection channel part is connected to said valve unit. Further, control means connected to said valve unit and said sensor unit are provided. The control means are arranged for controlling said valve unit based on signals obtained by said sensor unit.