Knowledgebase

Micronix Advanced Capabilities: Non-Magnetic

Non-Magnetic Positioners


Non-Magnetic

Magnetically sensitive applications require motion systems that are compatible with a defined magnetic environment. In practice, there are two primary requirements: positioners that must not generate a magnetic field, and positioners that must remain unaffected by external magnetic fields, which means using low-permeability materials. Both conditions need to be clearly specified, as they directly affect measurement accuracy, imaging quality, and overall system performance.

Magnetic permeability is a measure of how a material responds to a magnetic field. Materials with a relative permeability near 1 are generally considered non-magnetic because they neither concentrate nor distort magnetic fields. For example, aluminum has a relative permeability of approximately 1.000022, making it nearly invisible to magnetic fields, while soft iron has a relative permeability of 200-5000, which can strongly influence sensitive magnetic environments. Careful material selection, component sourcing, and assembly ensure the system meets the necessary permeability requirements.

 

Piezo Motor Technology, Intrinsically Non-Magnetic

Micronix piezo-based stages are the foundation for non-magnetic applications. Unlike electromagnetic motors, piezo elements operate through solid-state deformation rather than magnetic fields or current-driven coils. This means the motors themselves produce no magnetic field and are unaffected by external magnetic influences.

To support demanding applications, Micronix positioners are constructed using low-permeability, non-magnetic materials throughout. This allows the stage to deliver precise, repeatable motion while operating near sensitive magnetic equipment.

 

Micronix PPS-20 non-magnetic configuration with ceramic bearings

 

Materials Used in Non-Magnetic Configurations

Non-magnetic PPS stages achieve their performance through carefully selected materials, including:

  • Bare aluminum structural elements
  • Compatible encoders with glass scales
  • Ceramic and titanium bearings and hardware
  • Non-magnetic D-sub connectors for motor and encoder
  • Silver-braided cable jackets
  • Brass threaded inserts

 

These materials maintain strength, precision, and durability, resulting in compact PPS stages ideal for applications with strict magnetic requirements.

 

Material

Approx. Relative Permeability (μr)

Notes

Aluminum

1.000022

Lightweight, standard choice for structures

Ceramic

~1

Stable under load

Titanium

1.0002

Stronger, heavier, more costly compared to aluminum

Brass

1.0002

Corrosion-resistant

Stainless Steel (austenitic, e.g., 316)

1.00002 – 1.05

Low permeability if annealed; may be slightly magnetic depending on alloy

Silver (braided cable jackets)

~1

Flexible

Glass

1

Dimensionally stable

 

Chart: Material selection is determined in collaboration with engineering, where application requirements are assessed to ensure appropriate choices for both composition and magnetic permeability.