Mixing rotary positive displacement pump for micro dispensing

A dispensing apparatus capable of delivering quantities of a liquid product, comprising:

• a drive mechanism;
• at least one feed screw having a helical thread;
• a housing having a main body and a front body, where the main body is attached to the front body wherein the main body and the front body when attached form an internal cavity having a main cavity, a drive cavity, an output cavity and two input cavities;
• a disposable insert having a chamber, a first portion, a second portion, and two input channels where the disposable insert conformally fits within the internal cavity of the housing, such that a first component liquid is delivered through a first input channel of the at least two input channels to the chamber, and a second component liquid is delivered through a second input channel of the at least two input channels, where the first input channel and the second input channel are disposed so that interaction is hindered between the first component liquid and the second component liquid in either input channel;
• at least one feed screw having a helical thread and disposed in the chamber, where the at least one feed screw, rotated by the drive mechanism mixes the first and second component liquids to form a liquid product and discharges a precise amount of the liquid product from the chamber.