Syringe Pump Working Principle

Syringe pumps can be used in a wide variety of applications. They can accurately, evenly and continuously deliver fluids.

The working principle of a syringe pump is based on the correlation of piston displacement and volume injected. This minimal movement induces discrete phenomena which look like oscillations or pulses at low flow rates.

Motor

The motor is the basic machine in a syringe pump that drives the plunger to dispense the fluid. It’s also the most important part of the device. 

A syringe pump is a linear actuator that can deliver medications over long periods of time at precise flow rates and volumes. It’s different from an intravenous feeder, which relies on gravity to dispense liquids.

Syringe pumps are typically powered by stepper motors. The stepper motor is a small linear actuator that uses digital pulses to drive the syringe plunger.

The motor is programmed to control the angle of the syringe plunger’s linear motion by issuing pulses to the microcontroller through the pins in the syringe pump controller. A typical stepper motor is designed with 200 pulses/revolution (or 1.8deg/step), which determines the angle of the syringe’s linear motion.

Plunger

Syringe pumps are used in many research areas for precise dosing procedures and to precisely administer small amounts of reagents or mix minuscule volumes. They are also useful in a wide range of biomedical applications, especially when a low flow rate is required for a specific purpose or when the amount of fluid is limited.

A syringe pump includes a plunger driver that is pivotally attached to the motor. The plunger driver has a pair of asymmetric arms that capture the syringe plunger flange to retain it at the position of the plunger driver.

The plunger driver further includes a force concentrator that defines a pushing surface adapted to contact the plunger flange to push against it. The force concentrator focuses the force exerted by the driving surface of the plunger driver against the syringe plunger at a single point, providing more accurate measurement.

The plunger driver is capable of capturing syringes of widely varying sizes as one arm tends to move into a notch on an inside edge to accommodate a smaller syringe flange while the other tends to capture a larger syringe flange. This enables the device to be operated in a wide range of applications where syringes vary greatly in size.

Screw Rod

A threaded rod is a metal fastener that features threads cut into both ends, instead of heads or washers like standard screws. Typically longer and thicker than a standard screw, threaded rods are often used to secure two materials together or stabilise structures.

The tensile strength and durability of threaded rods make them a popular choice for use in a variety of applications. They are also easy to assemble and are reusable.

We offer threaded rod in various lengths and diameters to suit a range of purposes, as well as a variety of metal types including brass, stainless steel and nylon. They are also available in a zinc plated finish to increase corrosion resistance.

Syringe

Syringe pumps are positive-displacement pumps that transfer precise volumes of fluid at an accurate and consistent rate. These pumps are used in a variety of applications, from laboratory testing to medical procedures.

A syringe pump is made up of several components. These include the stepping motor, the driver, the screw rod and the syringe.

The stepper motor is responsible for precisely turning the screw rod that runs through the pusher block and the syringe plunger flange. This causes the pusher block to move, and the syringe plunger to pull back.

The syringe plunger is what moves the fluid from the syringe barrel into the syringe tube, which has a discharge orifice at the front end. The syringe may also have a needle or other device on the front end to inject the liquid.