The term lab-on-a-chip refers to a system that accommodates the entire functionality of a macroscopic laboratory on a chip. The micro-fluidic chip with the size of a credit card is usually made of plastic or glass, in which channels for the transport of liquids, analytes, or reactants are embedded. Biological, chemical or physical processes can take place that would otherwise only be possible in large reactors with the advantage of small volumes and low consumption of valuable chemicals and a high speed of analysis or reaction. Once a module has been designed, such chips can be produced in large numbers at a low price as a disposable product, e.g., in medical diagnostics.
The functionality of lab-on-a-chip systems is ensured by active components such as microvalves and pumps, and the pumps are needed in order to control the flow rate of liquid constantly, reproducibly and pulsation-free.
Syringe pumps are often applied if low flow rates are needed, but for long-term applications, the syringes previously had to be refilled manually. Spetec GmbH has developed a double-syringe pump in which the first syringe is emptied when the second is filled.
The photo shows the motor unit of Spetec GmbH Symax syringe pump. On the upper carrier plate, the two heads of the syringe holders with the spindle slot underneath can be seen. A quick-release device facilitates a quick replacement of both syringes.
The syringes with 5, 20 and 50 mL (made of polypropylene – PP) can be changed quickly and easily. The flow rates can be varied over a range of 6 orders of magnitude from 30 pL/s to 760 μL/s and several modules can be controlled individually. The control software enables the operation of up to 6 pumps in automatic continuous operation at the same time.