Linear Stages: Functions and Applications


The world’s present-day technological and industrial prowess is highly dependent on complex machinery systems, particularly those that optimize automaton and other processes that make modern engineering possible. In precision motion systems, one of the most well-known constituent modules is the linear stage. Also known as a translation stage, a linear stage is a device that allows the system to limit particular objects to a single axis or to an x-y axis of movement.

Each axis of a linear stage must be able to achieve 2 specific things: 

  • The first function is that it must be able to restrain the 6 degrees of freedom of an object in a 3-dimensional space to just translation along a straight line.

Take note that the 6 degrees of freedom includes forward-backward movement along the x-axis (surging),left-right movement along the  y-axis (swaying), and up-down movement along the z-axis (heaving), plus side to side tilting on the x-axis (rolling), forward-backward tilting on the y-axis (pitching), and left-right turning on the z-axis (yawing).

The translation along just a straight line is made possible by the incorporation of linear bearing guide ways between a platform and a base structure. These guide ways use bearings to move the platform—components that can come in different variants. The most familiar types include ball bearings, recirculating ball bearings, crossed roller bearings, and air bearings. 

  • The second function that a linear stage must achieve is the actuation of the object or payload in a way that provides very accurate accumulative motion along the guide way. The positioning of the platform along the guide way is typically achieved by a linear actuator integrated into the system.

There are various types of actuation technologies available, including those that use manual mechanisms, stepping motors, and lead screws, as well as linear motors and linear encoders. In terms of precision motor control, however, many industries generally consider the use of linear motors as the most reliable method of actuation.

Linear stages have numerous applications in a variety of industries. They are used in precision motion control systems in a wide range of instruments and machines, including those used for the following fields:

  • Optics – A branch of physics that studies the behavior of light.
  • Microscopy – A field of science concerned with the use of microscopes in order to visualize objects that cannot be seen with unaided human vision.
  • Photonics – The study of the properties and transmission of photons, like those in fiber optics.
  • Industrial automation and machining – Includes the manufacturing of medical components, machine tools, electronics, semiconductors, and many more.

Linear stages are very useful components of modern positioning systems. The best thing about them is that there are reliable manufacturers that can design them as custom solutions for virtually any type of application.