A chip includes a first chamber that stores a fluid, a second chamber that stores a mixing target which is to be mixed with the fluid, a flow path that allows a communication between the first chamber and the second chamber, and a valve that is provided in the flow path and capable of changing the flow path by change in shape by heating.

A chip includes a first chamber that stores a fluid, a second chamber that stores a mixing target which is to be mixed with the fluid, a flow path that allows a communication between the first chamber and the second chamber, and a valve that is provided in the flow path and capable of changing the flow path by change in shape by heating.

A closed system (100) for mixing fluids for use in a bioprocessing system, comprising: automated means for manipulating a tube weld (160) between a first tube fluidly connected to a first consumable (10-1) and another tube fluidly connected to a mixing consumable (10-3), said tube weld forming a closed fluid connection between the first consumable and mixing consumable; automated means for transferring a first fluid contained by the first consumable to the mixing consumable via the fluid connection; and automated means for determining a quantity of fluid transferred to or from the mixing consumable, wherein the system is further configured to manipulate a tube weld between a second tube fluidly connected to a second consumable (10-2) and said another tube fluidly connected to the mixing consumable, and transfer a second fluid therebetween to be mixed with the first fluid in the mixing consumable.