Axial Trapping
Axial Trapping - Related Videos
08:48
Stretching Short Sequences of DNA with Constant Force Axial Optical Tweezers
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Cited by 5 •
2011
We illustrate the use of a constant force axial optical tweezers to explore the mechanical properties of short DNA molecules. By stretching DNA axially, we minimize steric hindrances and artifacts arising in conventional lateral manipulation, allowing us to study DNA molecules as short as ~100 nm.
01:41
Social Traps
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2020
Social traps are negative situations where people get caught in a direction or relationship that later proves to be unpleasant, with no easy way to back out of or avoid. The concept was orignally introduced by John Platt who applied psychology to Garrett Hardin's "Tragedy of the Commons", where in New England herd owners could let their cattle graze in the common ground. This situation seems like a good idea, but an individual could have an advantage. If they owned more cows, the larger...
10:41
Method to Measure Tone of Axial and Proximal Muscle
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Cited by 5 •
2011
We have developed a device (Twister) to study the regulation of tonic muscle activity during active postural maintenance. Twister measures torsional resistance and muscular responses in standing subjects during twisting of the body axis. The device can be flexibly configured to study various aspects of tonic control across the neck, trunk, and/or hips.
11:45
Experimental Methods for Trapping Ions Using Microfabricated Surface Ion Traps
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Cited by 19 •
2017
This paper presents a microfabrication methodology for surface ion traps, as well as a detailed experimental procedure for trapping ytterbium ions in a room-temperature environment.
11:21
Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
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Cited by 1 •
2017
We present a parametric driving method to cool an ultracold Fermi gas in a crossed-beam optical dipole trap. This method selectively removes high-energy atoms from the trap by periodically modulating the trap depth with frequencies that are resonant with the anharmonic components of the trapping potential.
FAQs
Stable axial trapping requires the restoring gradient force to balance radiation pressure from the beam, along with other disturbances. The gradient force draws the microscopic object toward the focus, whereas radiation pressure acts as a competing influence along the beam direction. A trap remains stable only when these effects reach an appropriate balance rather than allowing the object to move away from the focus.
A high-numerical-aperture objective creates the steep intensity gradient needed for effective axial confinement. The focused laser field therefore produces a strong spatial change in intensity near the focus, allowing the gradient force to act as a restoring influence. This optical arrangement is central to positioning microscopic objects precisely along the beam axis without requiring direct physical contact.
The trapped position can be affected by the balance between the gradient force, radiation pressure, and other disturbances in the laboratory environment. Because axial stability depends on these competing effects, changes that alter the force balance may shift the microscopic object away from the focus. Recognizing this dependence is important when interpreting positioning or force measurements.
A basic workflow uses a laser beam and a high-numerical-aperture objective to create a focused field, places the microscopic object within the relevant region, and establishes confinement near the focus. The operator then uses the resulting stable position for manipulation or measurement. This sequence supports controlled handling while avoiding direct contact with the object.
Axial trapping can support precise manipulation and force measurements involving cells, microorganisms, biomolecules, and synthetic particles. By maintaining an object in a controlled position, the technique provides a basis for examining cellular mechanics and interactions. It can also help researchers assemble microscale structures, extending the method beyond simple positioning.
The approach is useful when bioengineering experiments require microscopic objects to be positioned without physical contact. It can be applied to cells, microorganisms, biomolecules, and synthetic particles in controlled laboratory environments. This noncontact capability supports studies of cellular mechanics and interactions while also enabling precise manipulation, force measurements, and microscale assembly.