A peristaltic pump drives fluid forward or backward inside of a flexible tube based on peristalsis. It is generally composed of a rotor, a number of rollers attached to the external circumference of the rotor, and a flexible tube fitted to the inside of a circular pump case. As the rotor rotates, rollers compress one part of the tube thus forcing the fluid to move through the tube. Additionally, as the tube opens to its natural state, fluid will be pulled into the tube. Typically, there should be at least two rollers occluding the tube, trapping between them a body of fluid.
Peristaltic pumps have broad applications involving liquid transfer and dispensing. Examples include the following: Juice production, food sauce dispensing, circulation of cell/tissue culture medium, cosmetic dispensing, nutrient supply, dispensing of spray liquid, ultrafiltration, acid/base dispensing, transfer of fuels, etc.