Optical Tweezers System with Video-Based Force Detection
Trap and manipulate molecules, particles, or cells and measure their forces with sub-pN resolution.
Overview
• Single or dual beam optical tweezers system based on an inverted microscope
• 3D real-time video-based force measurements with sub-pN resolution
• Huge free space above optical trap for all kinds of sample chambers and carriers
• Manipulate and navigate trapped objects with nanometer precision
• Easily extendable to fluorescence, STED, Raman spectroscopy, TIRF, or CLS
• Compact and ultrastable modular design
• No detector adjustments required
• Fast, easy, and reliable force calibration
• Customizable LabViewTM interface
• Combinable with time-resolved confocal microscopy
Applications
There is a wide field of applications that includes the investigation of single molecules and motor proteins, receptor-ligand-interactions, intramolecular elasticity, protein folding and unfolding, and controlled nanopore translocations. Scrutinize polymer elasticity or DNA overstretching phenomena in detail. Trap individual particles inside living cells or analyze interactions on artificial or natural membranes like cell surfaces. Last, but not least measuring Brownian motion of microscopic particles in various environments, tracking of particles, and rheological surveys (e.g. inside of microfluidic devices) are some of many further applications.
Huge Work Space
The PicoTweezers system is a high-performance video-based single or dual trap force spectroscopy instrument with decisive advantages over common optical tweezers systems with quadrant photodiode based position detection. In the PicoTweezers system the entire force detection and the laser beam control is located underneath the trapping lens and inside the upper deck of a two-deck Olympus microscope platform forming an extremely compact and robust instrument.
Due to the absence of a classical force detection module with a condenser lens confocally arranged to the trapping lens, PicoTweezers with its open space architecture provides an unrivalled free space above the optical trap. This open work space allows you to choose from a wide range of standard sample carriers, from Petri dishes, microscope slides and standard microtiter plates to microfluidic sample cartridges without size or height constraints.
The space around the optical trap is covered by a sturdy microscope housing serving as Faraday shielding, and is equipped with laser safety components, an IR-blocking observation window and side ports for easy sample chamber access.
Robustness by Design
Due to the absence of a force detection module above the optical trap, which is always prone to misalignments and the introduction of vibrations into experiments, the PicoTweezers system is a highly robust and sensitive instrument that requires only a single optical alignment procedure once at installation.
Modular Setup
The PicoTweezers system is a modular system you may compose individually according to your needs and experimental requirements, or use these modules as upgrades for existing optical tweezers or microscope systems.
Here, we provide a list of all modules with their respective specifications:
Microscope Platform
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Microscope Module |
Olympus IX73 Two-Deck Microscope Platform with Tilting Binocular Tube, IR-Safety Filtering and Camera Adapter • Lower Deck: Free for various modules: Can easily be equipped with Fluorescence, STED, CLS, or Raman • Upper Deck: Ionovation PicoTweezers Deck: Accommodates Trapping and Force Detection Modules • Working distance: 0.28 mm; NA 1.2; Cover slide correction: 0.13 – 0.21 mm
IR-Safety Microscope Housing with Controllable Illumination • Housing with laser safety shutter and IR-blocking observation window • Side ports for easy sample carrier access during experimentation
Overview Color Camera System • 2056 x 1542 pixel resolution, 57 Hz • IR-safety filtering
Data Station and Electronics • System specific, LabView pre-configured Windows PC with Monitor, Keyboard, Mouse • PicoTweezers software suite with programmable LabView™ interface • Full software control of illumination, Laser intensity, trapping, nano- and micropositioning |
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Objective Upgrade |
Customized IR-Enhanced 60x U Plan S Apo Water Immersion Objective • 50% increased transmission at 1064 nm compared to standard 60x U Plan S Apo objective • 50% increased maximum trapping force and trap stiffness |
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Microscope Module 2 |
Customized Module Based on Zeiss, Nikon, or Leica Microscope Platform |
Optical Trapping
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Trapping Module 1 |
1 W 1064 nm Unpolarized TEM00 cw Fiber Laser with M2 < 1.2 • Pigtail Single Mode Fiber Interface and Beam Expander • Stabilized power supply and controller with output power fluctuations < 1% • Dicroic beam coupling into optical path of microscope • Laser output power controllable between 1 and 100% in 1% steps
Generation of a single, stationary optical trap • Trap can be switched on and off both via software or manually • Maximum trapping force up to 300 pN with trap stiffness up to 0.35 pN/nm for 2 µm polystyrene bead in water • Position drift of trap < 0.4 nm in 2 minutes |
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Laser Upgrade 2 W
Upgrade for |
2 W 1064 nm Unpolarized TEM00 cw Fiber Laser with M2 < 1.2
Allows maximum trapping force up to 600 pN with trap stiffness up to 0.7 pN/nm for 2 µm polystyrene bead in water |
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Laser Upgrade 10 W
Upgrade for |
10 W 1064 nm Linearly Polarized TEM00 cw Fiber Laser with M2 < 1.1 • Adapted Beam Expander • Stabilized power supply and controller with output power fluctuations < 0.2%
Allows maximum trapping force up to 3000 pN with trap stiffness up to 3.5 pN/nm for 2 µm polystyrene bead in water |
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Trapping Module 2 |
2 W 1064 nm Linearly Polarized TEM00 cw Fiber Laser with M2 < 1.2 • Pigtail Single Mode Fiber Interface and Beam Expander • Stabilized power supply and controller with output power fluctuations < 1% • Dicroic beam coupling into optical path of microscope • Laser output power controllable between 1 and 100% in 1% steps
Generation of one stationary optical trap and a second, moveable optical trap • Both traps can be independently switched on and off, both via software or manually • Laser intensity distribution for both traps, from 0:100 to 100:0 in 5% steps • At 50:50 power distribution: Maximum trapping force up to 300 pN with trap stiffness up to 0.35 pN/nm • Position drift of stationary trap < 0.4 nm in 2 minutes • Second trap fully moveable and controllable in a lateral range (XY) of 60 x 60 µm • Absolute lateral position resolution at 100 Hz with closed-loop position control of second trap is 2 nm; • Position drift of movable trap is < 0.6 nm in 2 minutes |
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Laser Upgrade 10 W
Upgrade for |
10 W 1064 nm Linearly Polarized TEM00 cw Fiber Laser with M2 < 1.1 • Adapted Beam Expander • Stabilized power supply and controller with output power fluctuations < 0.2%
At 50:50 power distribution: Maximum trapping force up to 1500 pN with trap stiffness up to 1.7 pN/nm for |
Nano- and Micropositioning
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Nanopositioning Module
Optional Module, Recommended for Force Measurements |
Piezo-Controlled High Precision XYZ-Stage • Lateral range of 100 x 100 µm with closed-loop position control and resolution of 1 nm • Axial range of 20 µm with closed-loop position control and resolution of 0.1 nm • Open-loop travel of 130 x 130 x 25 µm • Capacitive sensor elements • Digital multi channel piezo controller with USB and Ethernet connection
Adapter board for sample carrier mounting |
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Nanopositioning Upgrade 1
Upgrade for Increased Movement Range |
Piezo-Controlled High Precision XYZ-Stage • Lateral range of 200 x 200 µm with closed-loop position control and resolution of 2 nm • Open-loop travel of 250 x 250 x 25 µm |
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Nanopositioning Upgrade 2
Upgrade for Increased Movement Range |
Piezo-Controlled High Precision XYZ-Stage • Lateral and axial range of 300 x 300 x 300 µm with closed-loop position control and resolution of 2 nm • Open-loop travel of 340 x 340 x 340 µm |
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Customized Nanopositioning Module |
Specifications According to Requirement |
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Piezo Controlled Micropositioning Module
Optional Module, Stand-alone, or Complement for Nanopositioning |
Ultrasonic Piezomotor-Controlled Precision XY-Stage • Movement range of 25 x 25 mm • Incremental movement of 0.3 µm • Sensor resolution of 0.1 µm • Self-locking and no heat generation when resting • Silent piezomotor drive • Digital ultrasonic piezomotor controller with USB and Ethernet connection |
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Customized Micropositioning Module |
Specifications According to Requirement |
3D-Force Measurement
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Force Measurement Module
Optional Module, Recommends Nano- or Micropositioning Module |
Video-Based Particle Detection for Reliable Real-Time 3D-Force Measurements • Open space architecture: No detection module on top of trapping objective required anymore! • Free space of at least 212 mm width, 264 mm depth and 75 mm height above optical trap • No spatial restriction for sample carriers • Compatible with Petri dishes, microscope slides and standard Microtiter plates • 400 Hz real-time force detection camera module • Force detection via particle tracking in stationary optical trap • No detector alignment or readjustment required • Easy force calibration routine • Scriptable measurement procedures • Force clamp measurements • Excellent long-term stability, force drift < 0.7 pN in 2 minutes when trap stiffness is 0.35 pN/nm or less • 0.4 pN force resolution at 400 Hz and 0.1 pN force resolution at 25 Hz when trap stiffness is 0.35 pN/nm or less • Illumination for force detection in wavelength band between 820 and 880 nm • No crosstalk between force detection and fluorescence, STED, CLS, or Raman |
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Beam Shaper
Upgrade for Force Measurement Module |
Engageable Beam Shaper for Improved Force Measurements on Reflective Optical Interfaces • Shapes laser beam profile to suppress backreflected and backscattered light • Allows interference-free axial force measurements in proximity of weakly reflective interfaces • Increases axial trapping stiffness by 40 % |