36 n PRECISION MOTION October 2026 www.drivesncontrols.com The hidden role of motion systems in pipetting In laboratories worldwide, scientists and industrialists rely on pipettes to measure and dispense precise volumes of liquids. Small inconsistencies can cascade into costly failed assays, repeat testing, or compliance risks, making accuracy and repeatability essential. As a result, air‑displacement micropipettes are often the primary choice in modern testing environments. Air‑displacement micropipettes became particularly visible during the global response to Covid‑19, where vital sample preparation required consistent, high‑volume pipetting and accelerated the uptake of electronic pipettes. Sample preparation has historically used both manual and electronic pipettes, but as laboratories increasingly prioritise efficiency and consistency, electronic pipettes have become the more popular choice. In an air‑displacement pipette, manual or electric action of a piston drives changes in the air column that aspirates and dispenses the liquid. Manual pipettes rely on an operator to compress and release a springloaded mechanism, generating the required pressure changes. While effective, this introduces variations in force, speed and timing, each of which can affect the resulting liquid volume. Repeated manual pipetting also presents ergonomic challenges, because frequent use can lead to discomfort and an increased risk of repetitive strain injuries for operators. Electronic pipettes remove much of that risk. Instead of a thumb-controlled plunger, a digital interface controls a motorised piston via a button. The outcome is more consistent aspiration and dispense profiles based on predictable motion, as well as reduced operator strain. Digital interfaces can improve the accuracy of volume settings and monitor output, while automated functions such as sequential multi‑dispensing, mixing and tip detection can further reduce the likelihood of human error. Digital interfaces can even store programs, reducing time needed for set-up, thus improving efficiency further. Motor selection As the first step in many laboratory workflows, pipetting performance has a direct impact on downstream results, reproducibility and operational efficiency. The choice of motor influences not only the motion performance and accuracy, but also calibration stability, maintenance demands, and long-term cost of ownership. Motors play a key role in the precision and accuracy of electronic pipettes by defining the force, speed, smoothness and positional fidelity of the piston’s movement. The two most common options are brushed DC motors and stepper linear actuators. Brushed DC motors translate DC power into rotational motion without complex electronics. Their smooth operation and straightforward control make them attractive for handheld devices such as pipettes. However, because pipetting requires linear movement, DC motors require additional components to convert the plane of movement. These systems need to meet strict specifications. Systems using DC motors typically incorporate feedback devices such as magnetic encoders, to ensure accurate piston positioning and compensate for backlash or mechanical tolerances in the screw-driven assemblies. Stepper linear actuators offer a more integrated alternative and are popular in electronic pipettes because of their direct linear motion and high positional resolution. A common approach is to Pipettes are a vital item of equipment in laboratories worldwide. Electronic pipettes are becoming increasingly popular, but their design requires a careful consideration of the choice of motor used to power them. This article from Portescap examines the options. Electronic pipetting systems are now widely used in laboratories around the world
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