16mm Stroke Compact Flat Voice Coil Actuator for Liquid Handling Dosing Pumps

The VCAP0020-0160-00A extends the flat planar voice coil family to a 16 mm stroke while keeping a compact 59 * 50 * 22.5 mm footprint and a 22.5 mm body height. Peak force is 20 N, continuous force at 25°C is 5.3 N, maximum voltage is 27.6 V and the back EMF constant is 4.4 V/m/s. The longer stroke is what makes this model useful for liquid handling: it covers the full travel of a 500 or 1000 microlitre syringe without any lever or screw reduction, so the piston follows the coil current directly and each dispense step becomes a pure force command instead of a mechanical transmission with lost motion.

Analytical instruments lose metering accuracy in three places: backlash in the syringe drive, stick slip between piston and barrel, and vibration transmitted from the drive train into the liquid column. A direct drive actuator addresses all three at once. There is no backlash to take up when the piston reverses between aspiration and dispense, so the volume delivered stays constant from the first shot to the millionth. Force control detects a blocked tip or a partially filled well long before a pressure sensor would, which lets the instrument flag the error in the same cycle instead of wasting a whole cartridge. Because the moving mass is small and the coil is rigidly coupled to the piston, the pump completes a full aspirate and dispense cycle at high frequency, shortening the protocol time of a plate based assay. Several coils can also be mounted side by side on a narrow pitch to build a multi channel head, each channel closing its own force or position loop, so a single blocked channel does not stop the others. An external linear encoder can be added whenever volumetric accuracy has to be verified rather than inferred.

Syringe and piston pumps in clinical chemistry and immunoassay analysers, next generation sequencing sample preparation, pipetting heads on laboratory workstations, reagent dispensing in point of care devices, precision adhesive and solder paste jetting, and micro dosing of oils, coolants or fragrances on production lines.

Q: How does the 16 mm stroke relate to syringe volume?
A: The stroke is the usable piston travel. A 1000 microlitre syringe with a 16 mm working stroke needs a barrel of roughly 8 to 9 mm inner diameter, while smaller volumes use a narrower barrel at the same stroke, which improves resolution.

Q: Can the actuator detect a clogged nozzle?
A: Yes. In current mode the coil force rises sharply when the piston meets resistance. A force threshold or a limit on the rate of change of the current feedback is normally enough to flag a blockage within one cycle.

Q: Is the actuator compatible with clean in place procedures?
A: The actuator itself is a dry electromagnetic device. In washable instruments it should be mounted behind a sealed bulkhead, with only the piston rod passing into the wet area.

Q: What is the resolution of a dispense step?
A: Resolution is set by the encoder and the drive. With a 1 µm linear encoder and a 9 mm barrel, one encoder count corresponds to about 0.06 microlitre, which is well inside typical assay tolerances.

Q: Can several units share one controller?
A: Yes. The low inductance coil is easy to drive from a multi axis amplifier, and each channel can run its own current loop, which is the usual arrangement for an eight channel pipetting head.