Simple to Use Nanopositioning Stage
Just add your objective and start focusing today!
Nanopositioning Stage for Objective Focusing – DOF-5
The DOF-5 nanopositioning stage for objective focusing has been engineered to offer increased travel (5 mm) and higher bandwidth (> 225 Hz) at a fraction of the cost of piezo stages with piezoelectric motors. By embedding the servo drive and motion controller inside the stage, complex cabling has been removed and the overall system cost has been reduced 50-60% less than competing offerings, while still maintaining equivalent or better performance. In addition, the DOF-5 can be connected directly to an Autofocus system for easy integration.
With > 5 mm of travel, the DOF-5 provides more engineering flexibility. The restricted travel of piezo systems (typically 100 to 300 microns) often leads to compromises in system performance. Attempts to extend the travel, such as employing lever amplification, dramatically decrease the focus stage’s resonant frequency and stiffness. The DOF-5’s increased travel removes the need for additional coarse positioning axes.
The DOF-5 includes stiff crossed roller bearings and brushless linear servo motor actuation, providing higher servo bandwidth and a better response for optical microscopy. The DOF-5 design is covered under U.S. Patent 10,367,436.
Features and Benefits
- Internal, constant force counterbalance
- Banking edges for quick, accurate, and repeatable alignment of the motion & optical axes
- Precision aligned objective mount is highly parallel to stage motion
- Objective can be pointed down for conventional microscope use, or up for an inverted microscope (objective is customer supplied)
- Convenient mounting from either the back or front
- High performance internal servo drive and control with linear encoder and half travel homing vane
- Single locking connector for power, communications, and high speed autofocus I/O
- Finely adjustable positive and negative end of travel stops prevent the objective from colliding with the sample
- Stiff linear bearing ensures fast move & settle performance with no out-of-plane compliance typical of flexure stages
|Piezo Flexure Stages||DOF Objective Focusing Stages|
|Typical piezo cost with controls ~$8,000 – $12,000.||Single nanopositioning system unit price with controls up to 50% less.|
|Flexure bearing results in off-axis motion and position dependent parasitic force.||Crossed roller bearing provides higher stiffness for faster moves. This results in increased throughput and longer nanopositioner life.|
|Stack or oscillating actuation have a non-linear response and bandwidth decreases as payload mass increases.||Brushless linear servo motor actuation provides higher servo bandwidth and a linear response for optical microscopy.|
|< 300 μm travel requires precise alignment and an additional coarse axis when more travel is required.||> 5 mm travel makes alignment easier. It also helps avoid microscope objective crashes and provides enough travel to clear interferences.|
|Oscillating piezos make a loud screeching noise.||A quiet servo is valued by lab workers.|
|Off-axis, complex controls are typically proprietary which leads to higher costs for piezo actuators.||Onboard controls result in a lower cost of ownership due to less complexity and fewer cables.|
What is “Nanopositioning”?
In the not-too-distant past, the precision tail-end of the bell curve in automation was often colloquially referred to as the “micropositioning” segment of the market. The term microposition derives from the fact that high-precision positioning systems were routinely operating at the micron level. Manufacturers in this space were specifying key system attributes such as Bi-directional repeatability, Accuracy, and Stability in units of microns. Such systems sufficiently filled industry demands from Life Science and Diagnostics, to Non-contact metrology, to the Tech sectors of Semiconductor, Data Storage, and Flat Panel Display.
Fast forward to our present day and no longer are such systems sufficient. Evolving industry needs in microscopy and biotechnology demand evolving levels of performance from precision positioning equipment manufacturers. As the features of interest across markets become smaller, the ability to position at the nanometer level becomes a market imperative. Dover Motion is proud to lead at the cutting edge of this new frontier of nanopositioning with groundbreaking products such as the revolutionary DOF-5 SmartStage™ Z axis focusing system and SmartStage Linear series single axis and XY systems.
This newest generation of products with repeatability, stability, and step-settle performance measured in nanometers more than addresses foreseeable industry needs. So, whether your cutting-edge instrument development is based on traditional diffraction-limited wide-field fluorescence microscopy; an increased resolution approach such as Confocal Laser Scanning Microscopy; or a super-resolution technique such as Structured Illumination Microscopy, Dover Motion’s aforementioned DOF-5 SmartStage Z axis stage is ready to provide all the objective nanopositioning performance required.
Advantages for Nanopositioning Microscopy
The use of a dedicated Z axis stage based on piezo actuators is currently the most commonly applied technique for high-performance and high-precision imaging; however, piezo-driven actuators have a number of very distinct limitations—despite their current dominance of the automated microscope focusing market.
The table below highlights the limitations of piezo stages and compares them with the features of our new DOF-5 objective focusing stage.
Fast, Accurate, and Repeatable 100 nm Moves
The above staircase plot displays position vs. time for ten consecutive 100 nm upward moves, followed by ten consecutive 100 nm downward moves. The data for the plot was taken at a 10-kHz sample rate, using a laser interferometer, and a plane mirror mounted at the base of a 300-gram objective. This staircase plot demonstrates the DOF-5’s ability to execute the very fast, accurate, and repeatable small moves typical in focusing applications.
High Throughput Steps with Very Low Jitter
The above zoom-in on a single 100 nm step from the staircase plot demonstrates the high-throughput focusing capabilities of the DOF-5 Z axis stage. In the above move, with an initial position stability of < +/- 3 nm, the objective performs a 100 nm step, settling into and remaining within a ± 7 nm window, in under 3 msec.
Nanometer Level Bi-directional Repeatability
The above plot shows a zoom box being shown over a pair of positions within the 100 nm staircase move sequence. The two selected positions are nominally the same, but are being approached from opposing directions. The position on the left was made during upward moves, while the position on the right was made while moving downward. As such, any lack of bidirectional repeatability will show up when comparing these two positions.
In this extreme zoom, with a vertical scale of 5 nm per division, the two positions (nominally at 400 nm) are each visible at high resolution. Despite being 2.8 seconds apart, and approached from opposing directions, the difference between the mean of the two positions during their 250 msec position hold is under 2 nm.
- Next-generation sequencing (NGS)
- Digital cell morphology
- Automated digital pathology
- Optical metrology instruments
- Semiconductor and nanotechnology imaging
- Digital microscopes
- High content imaging
- Automated cell counting
|Travel (mm)||> 5|
|Payload Mass (g)||100 – 900|
|Resolution (nm)||1.25 or 5|
|Servo Bandwidth (Hz)||≥ 225 Hz|
|Stability (nm RMS)||5|
|Step & Settle||100 nm within +/- 15 nm in < 15 ms|
|Bi-Directional Repeatability (nm) (for 500nm moves)||25|
|Homing Repeatability (µm)||1|
|Overall Size, excluding objective mount (mm)||77 x 82 x 30|
|Max Acceleration (m/s/s) with 1 kg||6|
|Max Velocity (mm/s)||125 (with 5 nm resolution)|
|Communications||RS232, RS485 full or half Duplex, CAN2.0B|
|Inputs||Step and direction|
Software & Manuals
|DOF-5, RS-232 Quick Start Guide||41-1598 Rev B||DOF-5 quick start guide with USB to RS-232 adapter for communications.|
|DOF-5, RS-485 Quick Start Guide||41-1599 Rev B||DOF-5 quick start guide with USB to RS-485 adapter for communications.|
|DOF-5, CAN Quick Start Guide||41-1600 Rev C||DOF-5 quick start guide with USB to CAN adapter for communications.|
|DOF-5 User Guide||41-1114 Rev B|
|DOF-5 Pro-Motion Software Guide||41-1212 Rev A|
The SmartStage XY Linear Positioners are a one of a kind stage with built in controls. Complete the form below to get pricing information and inquire about application support.