Magnetic Torque Tweezers
Magnetic Torque Tweezers - Related Videos
11:41
Magnetic Tweezers for the Measurement of Twist and Torque
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Cited by 16 •
2014
Magnetic tweezers, a powerful single-molecule manipulation technique, can be adapted for the direct measurements of the twist (using a configuration called freely-orbiting magnetic tweezers) and torque (using a configuration termed magnetic torque tweezers) in biological macromolecules. Guidelines for performing such measurements are given, including applications to the study of DNA and associated nucleo-protein filaments.
08:18
Torque
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2023
Source: Nicholas Timmons, Asantha Cooray, PhD, Department of Physics & Astronomy, School of Physical Sciences, University of California, Irvine, CA The goal of this experiment is to understand the components of torque and to balance multiple torques in a system to achieve equilibrium. Much like how a force causes linear acceleration, torque is a force that causes a rotational acceleration. It is defined as the product of a force and the distance of the force from the axis of rotation. If...
01:10
Torque
0 Views •
2023
Torque is an important quantity for describing the dynamics of a rotating rigid body. We see the application of torque in many ways in the world, such as when pressing the accelerator in a car, which causes the engine to apply additional torque on the drivetrain. Here, we define torque and provide a framework to create an equation to calculate torque for a rigid body with fixed-axis rotation. Torque can be considered as the rotational counterpart to force. Since forces change the translational...
10:08
Multiplexed Single-molecule Force Proteolysis Measurements Using Magnetic Tweezers
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Cited by 2 •
2012
In this article we describe the use of magnetic tweezers to study the effect of force on enzymatic proteolysis at the single molecule level in a highly parallelizable manner.
01:13
Torque On A Current Loop In A Magnetic Field
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2026
The most common application of magnetic force on current-carrying wires is in electric motors. These consist of loops of wire, which are placed between the magnets with a magnetic field. When current flows through the loops, the magnetic field applies torque, which causes the shaft to rotate, thus converting electrical energy to mechanical energy. Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
FAQs
Torque arises when the applied magnetic field points in a different direction from the bead’s magnetic moment. The field then tends to rotate the particle toward alignment, while the attached molecule or surface can resist that motion. By controlling the field direction, researchers impose twisting and examine how the connected system responds mechanically.
The bead’s rotational response can provide information about torsional stiffness, which describes resistance to twisting, and rotational drag, which describes resistance to angular motion. Changes in rotation can also indicate molecular conformational changes. These measurements connect controlled magnetic actuation with mechanical behavior at microscopic and molecular scales.
Magnetic Torque Tweezers apply torque without direct mechanical contact between the actuator and the tested system. This reduces the need for a physical manipulation interface and helps researchers probe molecules, surfaces, and soft materials under near-native conditions. The approach is therefore useful when mechanical responses must be measured while minimizing externally imposed contact.
The bead transmits the magnetic field’s rotational effect to an attached molecule or surface, allowing the experiment to impose a controlled twist. Its rotation also reports how that attached system responds. Relating field control to bead motion makes it possible to study resistance to rotation and detect changes in molecular mechanical state.
A magnetic bead is attached to the molecule or surface under study, and an applied magnetic field is directed relative to the bead’s magnetic moment. Researchers then control the field direction and measure bead rotation. Interpreting that rotational response yields mechanical information such as torsional stiffness, rotational drag, or conformational change.
Applications include the mechanics of DNA and proteins, the operation of molecular motors, and the behavior of soft materials. In each case, bead rotation supplies a way to examine responses to twisting at small scales. The technique is especially relevant when a system’s mechanical behavior or structural change is linked to rotational motion.
Controlling the magnetic field direction determines how the bead is driven relative to its magnetic moment. That control establishes the imposed rotational stimulus, while the resulting bead motion reflects the mechanical response of the attached system. Because the torque can be calibrated, researchers can relate observed rotation to quantitative torsional behavior.
The method translates magnetic-field control and bead rotation into measurements of mechanical response. This provides a physics-based way to examine torsional stiffness, rotational drag, and conformational changes in microscopic systems. In biophysics, that connection supports studies of DNA, proteins, molecular motors, and soft materials without requiring direct mechanical contact.