UHV-Compatible Custom 4-Axis Manipulator

Posted on Wednesday 28th October 2020 at 11:13

Arun Microelectronics specialises in the design and manufacture of in-vacuum motion systems and is a leading global manufacturer of vacuum compatible stepper motors for industrial, scientific and R&D applications.

A customer contacted us requiring a UHV-compatible 4-axis manipulator for an electron beam application. We worked closely with the customer to design a custom manipulator stage. The travel and load parameters were provided as well as some other key design requirements.


4-axis stage diagram


  • Vacuum: 1E−7 mBar
  • Temperature: −50 °C → 0 °C
  • Linear stage full step resolution: 5 μm (repeatability 1 μm)
  • Rotation stage full step resolution: 0.005 °
  • Coaxial independent detector arm

We designed a 4-axis manipulator capable of meeting the customer’s requirements. The stage includes a custom-design linear translator stage, two custom-design independent coaxial rotation stages and one of our standard LTVL-050 linear translator stages.

Two of our D57.1 UHV-compatible stepper motors were used to drive the independent sample and detector rotation stages via an anti-backlash gearing system.

Anti-backlash gearing system

The mechanism was constructed using only UHV-compatible materials, and assembled using UHV-compatible methods, in a dedicated ISO class 7 cleanroom at our factory in the United Kingdom.

Anti-backlash gearing system

An array of SMD3 Stepper Motor Drives were used to extensively test each axis of the manipulator stage, to ensure that it operates to AML’s high standard. The final specification is as follows:

Axis X1 R1 R2 X2
Motor type D42.1 D57.1 D57.1 D35.1
Stacking order 4 3 2 Sample
Lubrication Nyetorr® Nyetorr® Nyetorr® Nyetorr®
Guide type Crossed roller Ball bearing Ball bearing V-groove bearing
Load (g)     1000 500
Travel (deg/mm) ±25 mm ≥360° ≥360° ±25 mm
Resolution (per step) 5 μm 0.005° 0.005° 5 μm

Nyetorr® ultra-low outgassing grease was used on the motor bearings, leadscrews, worms and gears to increase the life of the mechanism.

Read more about vacuum mechanisms from AML here, or to discuss your in-vacuum motion enquiry, please do not hesitate to contact our dedicated team by emailing info@arunmicro.com.