We’ve improved the speci?cations of our popular Picomotor actuators so that they can be used in either vacuum (10-6 Torr) or UHV (10–9 Torr) environments as well as for VUV/EUV applications. Ideal for beam-steering and scienti?c vacuum motion-control applications, these Picomotor actuators offer vacuum compatibility down to 10-6 or 10–9 Torr with reliability you can count on. As with our Picomotor actuators, these vacuum versions offer the same 30-nm resolution over the full travel along with excellent long-term stability and high stiffness—including the ability to maintain its set position even in the power off state. And, with a tested lifetime of >15,000 cycles (>1 billion steps) over a 2-mm round-trip travel, you can integrate them into your system with con?dence.

As with all of our Picomotor actuators, these are easily incorporated into OEM designs for linear actuation as well as into optical mounts and stages for precision tip-tilt beam-steering adjustments.

Use the Model 8341 for times when you want rotation without translation.

Use these Picomotor actuators with our Model 8753 Intelligent Picomotor driver or Model 8703 TTL/Analog driver. Our modular iPico drivers and controllers provide the ability to build a system incorporating multiple standard and vacuum-compatible Picomotor actuators on the same control network.

Since these actuators and related optomechanical products have been designed speci?cally for semiconductor-capital-equipment manufacturers and the vacuum community, New Focus™ characterizes these clean products using standard Gas Chromatography-Mass Spectrometry analysis (GCMS). Such products have been tested and measured to outgas less than 5 ppm of volatile mass at 85 °C over three hours. Mass spectrograms detailing the exact outgassing compounds are available on request.

Standard Vacuum Picomotor Actuators

A Note on Our Vacuum-Compatible Picomotor Actuators in High-Radiation Applications

All our vacuum-compatible and ultrahigh-vacuum-compatible Picomotor actuators come with short, Te?on®-coated leads so you can make connections to your vacuum-chamber feedthrough. If, however, you are also working with x-rays or other high-radiation applications, we recommend ordering a custom version with Kapton®-coated wire extensions. While Te?on is compatible for use in high-vacuum environments, it is not recommended for use in high-radiation applications where, with repeated exposure to X-rays and other radiation, it can degrade and fall off, possibly causing electrical shorts. So, if you’re using our Picomotor actuators in a high-radiation application, contact our tech support for ordering these customized versions.

Lifetimes

Lifetime Speci?cations for Our Standard Picomotor™ Actuators

The lifetime of our standard Picomotor actuators is over 15,000 cycles. Our testing procedure is with a 5-lb axial load and over a round-trip travel range of 2 mm, or 1 mm out and 1 mm back. This translates to lifetimes of over 1 billion steps.

Closed Loop Vacuum Picomotor Actuators

• Compatible to 10–6 Torr
• Calibrated highly accurate positioning with all the bene?ts of our traditional Picomotor actuators
• Completely compatible with our modular iPico™ network controllers

This vacuum-compatible Model 8310-V closed-loop Picomotor actuator is ideal for applications where closed-loop control and position calibration is required in a clean environment. Just like the Model 8310 closed-loop Picomotor actuator (page 166), the Model 8310-V offers an integrated rotary encoder and home, forward, and reverse limit switches. It combines the best attributes of our vacuum-compatible Picomotor actuator—<30-nm resolution, >5 lbs (22 N) of force along with set-and-forget long-term stability and vacuum compatibility—with the added bene?ts of exceptional accuracy and ±1-µm bi-directional repeatability over the entire travel range.

Use the Model 8751-CL Intelligent closed-loop Picomotor driver (see ?Vacuum-Compatible Closed-Loop Picomotor™ Actuator) to control the Model 8310-V closed-loop Picomotor actuator. Our modular Intelligent Picomotor (iPico) drivers and controllers provide the ability to build a system incorporating multiple standard Picomotor actuators and one or more closed-loop Picomotor actuator at the same time on the same control network.

Technical Note

Tips for Achieving Nanometer-Scale Performance with the Closed-Loop Picomotor™ Actuator

The closed-loop Picomotor actuator offers <1-µm repeatability when approaching a target encoder count from any direction, <0.5-micron repeatability when approaching from a single direction, and 63.5-nm encoder resolution. (The actual inherent motor step size is considerably smaller—approximately 20 nm.) To achieve consistent nanometer-level performance, you need only keep a few precautions in mind.

Use a small amount of lubricant between the stainless-steel ball tip and the load surface to prevent wear and the generation of debris in the interface. We recommend Krytox GPL 205 or the low-vapor pressure grease, LVP LCT-42.

Keep the interface between the stainless-steel ball tip and the load surface clean of debris. Even small particles on the order of a micron can result in 0.1 to 10 micron differences between the encoder reading and the actual moved distance.

Push against smooth, hard, ?at surfaces only, such as the sapphire pads used in New Focus mirror mounts and translation stages. Pushing on aluminum or stainless-steel surfaces will wear out the ball tip. If the load surface is too soft, small amounts of material can build up in the interface between the ball tip and load surface resulting in surface roughness which can degrade repeatability.

Do not push against cone or v-shapes, especially in softer materials such as aluminum. When the ball wears against a cone or v-shape in softer materials, particle generation can lead to increased friction and torsional loads. These torsional loads can easily exceed the torsional load limit of 2.5 oz-in (0.018 N•m) thus stalling the motor.

Avoid damage to the screw threads. Do not touch the screw threads with any hard object—even lightly. To provide the ?ne resolution, the screw has very ?ne-pitch threads. If the threads are damaged, this damaged area will produce repeated excessive wear within the ?xed motor housing and signi?cantly reduce the lifetime of the motor.

Avoid clamping tightly on the motor’s housing. This can cause increased friction between the rotating inner screw and the ?xed exterior housing resulting in slowed motor motion or complete failure. This can also result in damaged screw threads.

Periodically examine the stainless-steel ball tip and the load surface for wear.

• Ultraclean for VUV/EUV and UHV environments
• <30-nm resolution with a non-rotating tip
• >5,000-cycle lifetime

The Model 8330 Picomotor actuator Ultra was designed speci?cally to minimize contamination and outgassing in clean-critical environments including vacuum ultraviolet (VUV) and extreme ultraviolet (EUV) applications. A special sealed bellow ensures the cleanliness of the actuators throughout its travel range. The actuators are ideal for precision motion-control and beam-steering applications in the semiconductor industry or in scienti?c laboratories down to pressures as low as 10–9 Torr.

The actuators offer <30-nm resolution (over a 3-mm travel range) along with exceptional long-term set-and-hold stability. They are extremely stiff and can hold their set position with no applied power. Because of their compact size, they can be easily incorporated into OEM designs for linear actuation as well as into optical mounts and stages for precision tip-tilt beam-steering adjustments. The non-rotating

tip results in even better motion resolution.

Use the Picomotor actuator Ultra with our Intelligent Picomotor driver modules. Combined with our standard closed-loop Picomotor driver and an external encoder, they can be operated as a closed-loop device over their full 3-mm range of travel. Limit switches and built-in hard stops protect the device and your equipment from over-travel.

The Picomotor actuator Ultra has been measured to outgas less than 0.1 ppm of volatile mass at 85 °C over three hours using standard Gas Chromatography-Mass Spectrometry analysis (GCMS). Mass spectrograms detailing the exact outgassing compounds are available on request.

We offer two cables (not included, see table on ?Picomotor™ Actuator Ultra) to connect the actuator to the driver—either directly (Model 8339) or through a standard feedthrough (Model 8338) and then to the driver.