Fields of application of high precision syringe pumps

Dosing of fluids in microfluidic environments for screening applications and miniaturized syntheses.



Creation of micro-serial sample streams in high throughput applications





Dosing of reagents with periodic gradients to create compartment sequences with variable concentration of the contents (creation of parameter rooms - e.g. at active agent search)


In industrial fields and in laboratory fields for high-precision dosing of fluids and for the creation of smallest, exactly defined fluid streams.




For various lab-on-chip applications e.g. DNA-amplification (PCR-chip)





Individual and serial processing of compartments and compartment-streams in microfluidic environments (enables serial high-throughput processing)

Pulsation free creation of continuous fluid streams?

For a growing number of applications in microfluidic environments it is important to generate fluid streams with a minimum of pulsation. By their good pulsation characteristics and the PID-controlled drives the high-precision syringe pumps of neMESYS series are highly qualified for this application fields. How can this good pulsation characteristic be reached? The following features are setting off the neMESYS dosing units against conventional syringe pumps or diluters and ensure an almost pulsation-free generation of fluid streams:

	conventional	neMESYS
drive	stepper drive	servo drive
position control	unregulated	closed loop PID control
velocity control	steady velocity	closed loop PID control
linear unit	standard	high-precision-axis (1 mm pitch)
spindle drive	standard	ball screw drive
gear ratio	none	up to 29:1
pulsation characteristics (dosing of a fluid stream of 5 µl/s with fluorescent colouring) pictures: Friedrich-Schiller-Unversity Jena

Measurement of the absence of pulsation

The absence of pulsation was measured at the Institute for Physical High Technology in Jena by use of a technique for pulsation measurement in smallest fluid amounts.

For these measurements a flow sensor was used. This sensor consists of a micro channel with integrated heating element and temperature sensors, united in a small glass chip.

Six temperature sensors are arranged in flow direction symmetrically to the heating structure. The flow sensor uses the heat transfer coupled to a volume flow to gain the sensor signal.

For this purpose a defined energy is coupled into the fluid by the heater. This causes a symmetric temperature profile in the channel. If a volume flow is streaming through the measuring channel then it is coupled with a heat transfer. This causes an interference of the symmetric temperature profile in the channel. This disturbance variable is used for the measurement of the volume flow.

From the measured values the frequency spectrum can be determined by use of a Fourier transformation. From the graph of the spectrum it is possible to analyse at which frequencies there is pulsation.