The simplest version simply dispenses an allotted volume of liquid from a motorized
pipette or
syringe; more complicated machines can also manipulate the position of the dispensers and containers (often a
Cartesian coordinate robot, and/or integrate additional laboratory devices, such as centrifuges, microplate readers, heat sealers, heater/shakers, bar code readers, spectrophotometric devices, storage devices and incubators. More complex liquid handling workstations can perform multiple
Laboratory Unit Operations such as sample transport, sample mixing, manipulation and incubation, as well as transporting vessels to/from other workstations. An alternative category of liquid handlers mimics the operations of humans, by performing liquid transfers as humans would do. These robots achieve the cartesian, 3-axis movements implemented in larger workstations, by means of an arm. == Modularity ==